2024/12/05 更新

お知らせ

 

写真a

フクダ ジユンイチ
福田 順一
FUKUDA JUNICHI
所属
理学研究院 物理学部門 教授
理学部 物理学科(併任)
理学府 物理学専攻(併任)
職名
教授
連絡先
メールアドレス
プロフィール
ソフトマターの統計物理学,計算物理学.その中でも主に液晶を対象として,自己組織的な秩序構造形成,そのダイナミクスのメカニズム,およびそれらの秩序構造の光学的性質の研究を行なっている.

学位

  • 京都大学博士(理学)

経歴

  • JST ERATO横山液晶微界面プロジェクト 産業技術総合研究所(ナノテクノロジー研究部門,ナノシステム研究部門,機能化学研究部門,機能材料コンピューテショナルデザイン研究センター)   

    JST ERATO横山液晶微界面プロジェクト 産業技術総合研究所(ナノテクノロジー研究部門,ナノシステム研究部門,機能化学研究部門,機能材料コンピューテショナルデザイン研究センター)

研究テーマ・研究キーワード

  • 研究テーマ: ソフトマターの統計物理学,計算物理学

    研究キーワード: ソフトマター,液晶,高分子,コロイド

    研究期間: 1999年4月

受賞

  • Outstanding Referee

    2020年1月   アメリカ物理学会   American Physical Society がReferee Reportの"quality, number, and timeliness"を評価して毎年授与しているものである.

     詳細を見る

    Outstanding Refereeはアメリカ物理学会(American Physical Society)によって選ばれる賞で,Physical Review誌などのレフェリー活動で,数,質,迅速性の観点から顕著な業績を挙げたレフェリーに毎年授与されるものである.

  • 日本液晶学会賞論文賞A

    2019年9月   日本液晶学会  

     詳細を見る

    本研究は、キラル液晶の薄膜において半整数のスカーミオン数をもつ半スカーミオン (連続場に生じる渦状の励起構造) が自発的に形成されることを世界で初めて実証したものである。詳細な光学顕微鏡観察から、大きさ数百 ㎚ 程度の半スカーミオンがヘキサゴナルな格子を形成したり、孤立した粒子として振舞ったりすることを明らかにし、さらに、液晶配向シミュレーションおよびベクトル電磁界解析により、実験によって得られた顕微鏡像を理論的に再現することに成功した。キラル液晶が様々な凝縮系で注目を集めるスカーミオンの生成や制御を探索する新たなプラットフォームとなりうることを示した点、および液晶の自己組織材料としての新たな可能性を提示したことが評価された。

  • 日本液晶学会賞論文賞A

    2012年9月   日本液晶学会  

  • 日本物理学会若手奨励賞(領域12)

    2008年3月   日本物理学会  

  • 日本液晶学会賞奨励賞

    2002年10月   日本液晶学会  

論文

  • Multi-step nucleation of anisotropic molecules 査読 国際誌

    @K.Z. Takahashi, @T. Aoyagi J. Fukuda

    Nature Communications   12   5278   2021年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    従来の古典核生成理論において、さまざまな物質のナノ構造は1段階~2段階のプロセスを経て生成されると説明されていた。しかし今回、液晶の場合にはより複雑な3段階のプロセスを経ることを発見するとともに、そのメカニズムの解明にも成功した。本解析技術は液晶だけでなくポリマーや生体材料などさまざまな物質の解析にも応用可能なため、幅広い高機能材料の創製につながる。

    DOI: https://doi.org/10.1038/s41467-021-25586-4

    その他リンク: https://doi.org/10.1038/s41467-021-25586-4

  • Spontaneous formation and dynamics of half-skyrmions in a chiral liquid-crystal film 査読

    Andriy Nych, Jun-ichi Fukuda, Uliana Ognysta, Slobodan Zumer, Igor Musevic

    NATURE PHYSICS   13 ( 12 )   1215 - +   2017年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Skyrmions are coreless vortex-like excitations emerging in diverse condensed-matter systems, and real-time observation of their dynamics is still challenging. Here we report the first direct optical observation of the spontaneous formation of half-skyrmions. In a thin film of a chiral liquid crystal, depending on experimental conditions including film thickness, they form a hexagonal lattice whose lattice constant is a few hundred nanometres, or appear as isolated entities with topological defects compensating their charge. These half-skyrmions exhibit intriguing dynamical behaviour driven by thermal fluctuations. Numerical calculations of real-space images successfully corroborate the experimental observations despite the challenge because of the characteristic scale of the structures close to the optical resolution limit. A thin film of a chiral liquid crystal thus offers an intriguing platform that facilitates a direct investigation of the dynamics of topological excitations such as half-skyrmions and their manipulation with optical techniques.

    DOI: 10.1038/NPHYS4245

  • Three-dimensional positioning and control of colloidal objects utilizing engineered liquid crystalline defect networks 査読

    H. Yoshida, K. Asakura, J. Fukuda, M. Ozaki

    NATURE COMMUNICATIONS   6   2015年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Topological defects in liquid crystals not only affect the optical and rheological properties of the host, but can also act as scaffolds in which to trap nano or micro-sized colloidal objects. The creation of complex defect shapes, however, often involves confining the liquid crystals in curved geometries or adds complex-shaped colloidal objects, which are unsuitable for device applications. Using topologically patterned substrates, here we demonstrate the controlled generation of three-dimensional defect lines with non-trivial shapes and even chirality, in a flat slab of nematic liquid crystal. By using the defect lines as templates and the electric response of the liquid crystals, colloidal superstructures are constructed, which can be reversibly reconfigured at a voltage as low as 1.3V. Three-dimensional engineering of the defect shapes in liquid crystals is potentially useful in the fabrication of self-healing composites and in stabilizing artificial frustrated phases.

    DOI: 10.1038/ncomms8180

  • A liquid crystalline chirality balance for vapours 査読

    Takuya Ohzono, Takahiro Yamamoto, Jun-ichi Fukuda

    NATURE COMMUNICATIONS   5   2014年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Chiral discrimination of vapours plays an important role in olfactory perception of biological systems and its realization by artificial sensors has been an intriguing challenge. Here, we report a simple method that tangibly visualizes the chirality of a diverse variety of molecules dissolved from vapours with high sensitivity, by making use of a structural change in a periodic microstructure of a nematic liquid crystal confined in open microchannels. This microstructure is accompanied by a topological line defect of a zigzag form with equal lengths of 'zig' and 'zag.' We find that a tiny amount of vapour of chiral molecules injected onto the liquid crystal induces the imbalance of 'zig' and 'zag' depending on its enantiomeric excess within a few seconds. Our liquid- crystal-based 'chirality balance' offers a simple, quick and versatile chirality-sensing/-screening method for gas-phase analysis (for example, for odours, environmental chemicals or drugs).

    DOI: 10.1038/ncomms4735

  • Zigzag line defects and manipulation of colloids in a nematic liquid crystal in microwrinkle grooves 査読

    Takuya Ohzono, Jun-ichi Fukuda

    NATURE COMMUNICATIONS   3   2012年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Spatially confined liquid crystals exhibit non-uniform alignment, often accompanied by self-organised topological defects of non-trivial shape in response to imposed boundary conditions and geometry. Here we show that a nematic liquid crystal, when confined in a sinusoidal microwrinkle groove, exhibits a new periodic arrangement of twist deformations and a zigzag line defect. This periodic ordering results from the inherent liquid crystal elastic anisotropy and the antagonistic boundary conditions at the flat liquid crystal-air and the curved liquid crystal-groove interfaces. The periodic structure can be tuned by controlling the groove geometry and the molecular chirality, which demonstrates the importance of boundary conditions and introduced asymmetry for the engineering of topological defects. Moreover, the kinks in the zigzag defects can trap small particles, which may afford a new method for manipulation of colloids. Our system, which uses easily fabricated microwrinkle grooves, provides a new microfabrication method based on the arrangement of controllable defects.

    DOI: 10.1038/ncomms1709

  • Ring Defects in a Strongly Confined Chiral Liquid Crystal 査読

    Jun-ichi Fukuda, Slobodan Zumer

    PHYSICAL REVIEW LETTERS   106 ( 9 )   2011年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We find numerically that a regular array of isolated ring defects can exist as a stable state in a highly chiral liquid crystal confined in a thin cell imposing fixed planar anchoring at the parallel confining surfaces. This peculiar defect structure can be stable when the cell thickness d is around 3/4 of the helical pitch p. A cell of thickness 3p/4 with parallel surface anchoring is incompatible with helical alignment that favors d mp/2 (with m being an integer). Formation of ring defects can thus be regarded as a result of frustrations between the helical alignment with a specific pitch and the confining surfaces that prevent it.

    DOI: 10.1103/PhysRevLett.106.097801

  • Quasi-two-dimensional Skyrmion lattices in a chiral nematic liquid crystal 査読

    Jun-ichi Fukuda, Slobodan Zumer

    NATURE COMMUNICATIONS   2 ( 1 )   2011年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Skyrmions are particle-like topological entities in a continuous field that have an important role in various condensed matter systems, including two-dimensional electron gases exhibiting the quantum Hall effect, chiral ferromagnets and Bose-Einstein condensates. Here we show theoretically, with the aid of numerical methods, that a highly chiral nematic liquid crystal can accommodate a quasi-two-dimensional Skyrmion lattice as a thermodynamically stable state, when it is confined to a thin film between two parallel surfaces imposing normal alignment. A chiral nematic liquid crystal film can thus serve as a model Skyrmion system, allowing direct investigation of their structural properties by a variety of optical techniques at room temperatures that are less demanding than Skyrmion systems discussed previously.

    DOI: 10.1038/ncomms1250

  • Novel Defect Structures in a Strongly Confined Liquid-Crystalline Blue Phase 査読

    Jun-ichi Fukuda, Slobodan Zumer

    PHYSICAL REVIEW LETTERS   104 ( 1 )   2010年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In our numerical study based on a phenomenological description of strongly confined liquid crystalline blue phase I (BP I), we find several novel structures characterized by specific configurations of topological disclination lines. The thickness of the system is of the order of the dimension of the unit cell of the bulk BP I and the confining surfaces adopts homeotropic anchoring. The structures include an array of double-helix disclination lines accompanied by an orthorhombic lattice of double-twist cylinders, and two parallel arrays of winding disclination lines almost perpendicular to each other.

    DOI: 10.1103/PhysRevLett.104.017801

  • Surface-groove-induced azimuthal anchoring of a nematic liquid crystal: Berreman's model reexamined 査読

    Jun-ichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    PHYSICAL REVIEW LETTERS   98 ( 18 )   2007年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    To account for azimuthal surface anchoring of a nematic liquid crystal, Berreman [Phys. Rev. Lett. 28, 1683 (1972)] proposed a simple model attributing the surface anchoring to the elastic distortion of the liquid crystal induced by the grooves of a surface. He showed that the surface anchoring energy is proportional to sin(2)phi, with phi being the angle between the director at infinity and the direction of the surface grooves. We argue that his assumption of negligibly small azimuthal distortion of the nematic is not valid. Proper treatment of the azimuthal distortion reveals that the Berreman's model should yield a surface anchoring energy proportional to sin(4)phi. This implies that surface grooves alone cannot contribute to the surface anchoring coefficient in the usual Rapini-Papoular sense.

    DOI: 10.1103/PhysRevLett.98.187803

  • Separation-independent attractive force between like particles mediated by nematic-liquid-crystal distortions 査読

    Junichi Fukuda, Hiroshi Yokoyama

    Physical Review Letters   94 ( 14 )   2005年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically with the aid of the Landau-de Gennes continuum theory the interaction between two spherical particles carrying the same topological charges +1 mediated by the elastic distortion of a nematic liquid crystal. We consider the case where an escaped nontopological ring disclination is situated between the particles; the director is continuous everywhere and no counterdefects are present. We find that the interaction is attractive and its potential energy depends linearly on the interparticle distance D. This behavior yields the D-independent interaction force, which was observed experimentally by Poulin, Cabuil, and Weitz [Phys. Rev. Lett. 79, 4862 (1997)] in the presence of narrow strings of birefringent regions ("bubble-gum" configuration) between the particles.

    DOI: 10.1103/PhysRevLett.94.148301

  • Capillary condensation in liquid-crystal colloids 査読

    Holger Stark, Junichi Fukuda, Hiroshi Yokoyama

    Physical Review Letters   92 ( 20 )   2004年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The capillary condensation between two spherical particles dispersed in the isotropic phase of a nematic liquid crystal was investigated. The interaction energies due to the formation of capillary bridges that reproduce experimental observations were calculated within the Landau-de Gennes theory. The fluctuations in the particle cluster were described by an effective two-state system, close to the critical point of the transition line separating the no-bridge from the bridge configuration. It was found that for the small particles, the transition line vanishes and the shape of interaction potential depends on particle size.

    DOI: 10.1103/PhysRevLett.92.205502

  • Interaction between two spherical particles in a nematic liquid crystal 査読

    Junichi Fukuda, Holger Stark, Makoto Yoneya, Hiroshi Yokoyama

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   69 ( 4 1 )   2004年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The interaction between two spherical particles in a nematic liquid crystal was investigated. The Landau-de Gennes continuum theory was adopted in terms of a second-rank tensor order parameter for the description of the orientational order of a nematic liquid crystal. An adaptive mesh refinement method was used that proves to be an efficient way of dealing with topological defects, whose core size is much smaller than the particle size. It is observed that when the dipoles composed of a particle and a hyperbolic hedgehog defect align in parallel directions, the interaction potential is attractive for large particle separations.

  • Oscillating edge current in polar active fluid

    Matsukiyo, H; Fukuda, J

    PHYSICAL REVIEW E   109 ( 5 )   054604   2024年5月   ISSN:2470-0045 eISSN:2470-0053

     詳細を見る

    記述言語:英語   出版者・発行元:Physical Review E  

    Dense bacterial suspensions exhibit turbulent behavior called bacterial turbulence. The behavior of the bulk unconstrained bacterial turbulence is described well by the Toner-Tu-Swift-Hohenberg (TTSH) equation for the velocity field. However, it remains unclear how we should treat boundary conditions on bacterial turbulence in contact with some boundaries (e.g., solid walls). To be more specific, although the importance of the edge current, the flow along the boundary, has been demonstrated in several experimental studies on confined bacterial suspensions, previous numerical studies based on the TTSH equation employ nonslip boundary conditions and do not seem to properly describe the behavior of bacteria near the boundaries. In this paper, we impose a slip boundary condition on the TTSH equation to describe the bacterial motion at boundaries. We develop a method to implement the slip boundary condition. Using this method, we have successfully produced edge current and discovered that the direction of the edge current temporally oscillates. The oscillation can be attributable to the advection term in the TTSH equation. Our paper demonstrates that boundary conditions could play an important role in the collective dynamics of active systems.

    DOI: 10.1103/PhysRevE.109.054604

    Web of Science

    Scopus

    PubMed

  • Formation of Topological Defects at Liquid / Liquid Crystal Interfaces in Micro-Wells Controlled by Surfactants and Light 査読 国際誌

    @K. Katayama, @T. Yoshimura, @S. Yamashita, @H. Teratani, @T. Murakami, @H. Suzuki and J. Fukuda

    Soft Matter   19   6578 - 6588   2023年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: https://doi.org/10.1039/D3SM00838J

  • Simulation of a cholesteric blue phase cell with large but finite thickness 査読 国際誌

    J. Fukuda

    Frontiers in Soft Matter   2   1011618   2022年11月   eISSN:2813-0499

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Frontiers Media SA  

    We investigate the structure of a cholesteric blue phase (BP) liquid crystal cell of finite thickness under an electric field normal to the planar surfaces confining the liquid crystal. We carry out large scale simulations to consider cases in which the thickness of the BP liquid crystal is approximately 40 times the BP lattice constant (typical thickness in experiments), larger than that of previous simulation studies. Our calculations clearly demonstrate that the number of periodic structures along the thickness direction (thickness divided by the lattice constant) is discretized by the presence of confining surfaces. The stability of the so-called BP X structure over the BP I under the electric field, as well as the electrostriction, is confirmed. The metastability of the BP X structure after the cessation of the electric field, demonstrated in a recent experiment [Nat. Mater. 19, 94 (2020)] is also shown. We also perform calculations for the reflection spectra of the BP structures, and clearly observe the shift of the reflection peak due to electrostriction. Our study demonstrates the role of finite thickness on the behavior of a BP cell.

    DOI: 10.3389/frsfm.2022.1011618

    researchmap

  • Regression analysis for predicting the elasticity of liquid crystal elastomers 査読 国際誌

    Doi, H; Takahashi, KZ; Yasuoka, H; Fukuda, J; Aoyagi, T

    SCIENTIFIC REPORTS   12 ( 1 )   19788   2022年11月   ISSN:2045-2322 eISSN:2045-2322

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Scientific Reports  

    It is highly desirable but difficult to understand how microscopic molecular details influence the macroscopic material properties, especially for soft materials with complex molecular architectures. In this study we focus on liquid crystal elastomers (LCEs) and aim at identifying the design variables of their molecular architectures that govern their macroscopic deformations. We apply the regression analysis using machine learning (ML) to a database containing the results of coarse grained molecular dynamics simulations of LCEs with various molecular architectures. The predictive performance of a surrogate model generated by the regression analysis is also tested. The database contains design variables for LCE molecular architectures, system and simulation conditions, and stress–strain curves for each LCE molecular system. Regression analysis is applied using the stress–strain curves as objective variables and the other factors as explanatory variables. The results reveal several descriptors governing the stress–strain curves. To test the predictive performance of the surrogate model, stress–strain curves are predicted for LCE molecular architectures that were not used in the ML scheme. The predicted curves capture the characteristics of the results obtained from molecular dynamics simulations. Therefore, the ML scheme has great potential to accelerate LCE material exploration by detecting the key design variables in the molecular architecture and predicting the LCE deformations.

    DOI: 10.1038/s41598-022-23897-0

    Web of Science

    Scopus

    PubMed

    researchmap

    その他リンク: https://doi.org/10.1038/s41598-022-23897-0

  • Exotic structures of a thin film of chiral liquid crystals: a numerical study based on the Landau-de Gennes theory 招待 査読 国際誌

    Fukuda, J

    LIQUID CRYSTALS REVIEWS   10 ( 1-2 )   69 - 90   2022年6月   ISSN:2168-0396 eISSN:2168-0418

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Liquid Crystals Reviews  

    Chiral liquid crystals exhibit various intriguing ordered structures arising from helical distortions of the orientational order allowed by chirality. We present our numerical studies on such exotic structures of chiral liquid crystals, particularly focusing on those in a thin film whose thickness is on the order of or smaller than the characteristic helical pitch of the liquid crystal. We first review the Landau–de Gennes continuum theory we use in our calculations, in which the orientational order is described by a second-rank tensor (Formula presented.) and the free energy of a liquid crystal is given as a functional of (Formula presented.). We show that a thin film of a chiral liquid crystal can exhibit a diverse variety of ordered structures involving topological line defects (disclination lines), depending on film thickness, temperature, and type of surface anchoring (normal, planar, and planar degenerate). Such exotic structures include a hexagonal lattice of Skyrmions, a whirl-like localized structure that finds in its place in a wide variety of condensed matter systems. A thin film of a chiral liquid crystal thus provides an interesting platform for the investigation of exotic structures of orientational order arising from the frustration between the bulk ordering and the spatial confinement with surface anchoring.

    DOI: 10.1080/21680396.2022.2077256

    Web of Science

    Scopus

    researchmap

  • Structure of twin boundaries of cholesteric blue phase I 査読 国際誌

    #A. Yamashita, J. Fukuda

    Physical Review E   105   044707   2022年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: https://doi.org/10.1103/PhysRevE.105.044707

    その他リンク: https://link.aps.org/doi/10.1103/PhysRevE.105.044707

  • Liquid crystalline half-Skyrmions and their optical properties 招待 査読 国際誌

    J. Fukuda, @A. Nych, @U. Ognysta, @S. Zumer, @I. Musevic

    Annalen der Physik   534   2100336   2022年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: https://doi.org/10.1002/andp.202100336

    その他リンク: https://doi.org/10.1002/andp.202100336

  • 液晶エラストマーの力学特性に関するインフォマティクス解析

    保岡 悠, 田頭 健司, 土居 英男, 高橋 和義, 福田 順一, 青柳 岳司

    日本ゴム協会誌   95 ( 2 )   54 - 59   2022年   ISSN:0029022X eISSN:18840442

     詳細を見る

    記述言語:日本語   出版者・発行元:一般社団法人 日本ゴム協会  

    <p>Liquid crystal elastomers (LCEs) are a relatively new class of materials that display soft elasticity, that is, they can be deformed without resistance. Furthermore, LCEs show a rapid and accurate response to external stimuli such as electric, magnetic, and thermal fields. For this reason, it is expected to be applied to actuators or sensors. In order to apply these characteristics to devices, we tried to predict the characteristics of LCE by simulation. First of all, we developed an extended coarse-grained LCE model to enable simulation of systems of various architectures. Our model is a hybrid of Gay-Berne particles and Lennard-Jones particles, based on previously reported LCE modeling techniques. By using molecular dynamics (MD) method, the stress-strain curves as the response to an external force were obtained, and soft elasticity was clearly observed. Then, the regression analysis using machine learning (ML) was conducted on the results of the stress-strain curves of the MD simulations. The results indicated that spacing for a room for mobility of mesogenic units in the design variables of LCE molecules affected elasticity. In addition, the R-squared value of regression curve for stress-strain curves was 0.821, which indicates a strong correlation between the MD data and ML results. Finally, the estimation method of molecular structure from coarse-grained model is discussed.</p>

    DOI: 10.2324/gomu.95.54

    CiNii Research

  • In Situ Optical Characterization of Twinning in Liquid Crystalline Blue Phases 査読 国際誌

    @Y. Zhang, @H. Yoshida, @S.-Y. Cho, J. Fukuda, @M. Ozaki

    ACS APPLIED MATERIALS & INTERFACES   13 ( 30 )   36130 - 36137   2021年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1021/acsami.1c06873

    その他リンク: https://doi.org/10.1021/acsami.1c06873

  • Molecular architecture dependence of mesogen rotation during uniaxialelongation of liquid crystal elastomers 査読 国際誌

    @H. Yasuoka, @K. Z. Takahashi, J. Fukuda, @T. Aoyagi

    Polymers   229   123970   2021年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: https://doi.org/10.1016/j.polymer.2021.123970

    その他リンク: https://doi.org/10.1016/j.polymer.2021.123970

  • Directed self-assembly of soft 3D photonic crystals for holograms with omnidirectional circular-polarization selectivity

    SeongYong Cho, Misaki Takahashi, Jun-ichi Fukuda, Hiroyuki Yoshida, Masanori Ozaki

    Communications Materials   2021年3月

     詳細を見る

    記述言語:その他   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1038/s43246-021-00146-x

  • Lattice orientation of cholesteric blue phases in contact with surfaces enforcing unidirectional planar anchoring

    Jun-ichi Fukuda, Slobodan Žumer

    Physical Review Research   2020年9月

     詳細を見る

    記述言語:その他   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1103/PhysRevResearch.2.033407

  • Machine learning-aided analysis for complex local structure of liquid crystal polymers 査読

    Hideo Doi, Kazuaki Z. Takahashi, Kenji Tagashira, Jun ichi Fukuda, Takeshi Aoyagi

    Scientific reports   9 ( 1 )   2019年12月

     詳細を見る

    記述言語:英語  

    Elucidation of mesoscopic structures of molecular systems is of considerable scientific and technological interest for the development and optimization of advanced materials. Molecular dynamics simulations are a promising means of revealing macroscopic physical properties of materials from a microscopic viewpoint, but analysis of the resulting complex mesoscopic structures from microscopic information is a non-trivial and challenging task. In this study, a Machine Learning-aided Local Structure Analyzer (ML-LSA) is developed to classify the complex local mesoscopic structures of molecules that have not only simple atomistic group units but also rigid anisotropic functional groups such as mesogens. The proposed ML-LSA is applied to classifying the local structures of liquid crystal polymer (LCP) systems, which are of considerable scientific and technological interest because of their potential for sensors and soft actuators. A machine learning (ML) model is constructed from small, and thus computationally less costly, monodomain LCP trajectories. The ML model can distinguish nematic- and smectic-like monodomain structures with high accuracy. The ML-LSA is applied to large, complex quenched LCP structures, and the complex local structures are successfully classified as either nematic- or smectic-like. Furthermore, the results of the ML-LSA suggest the best order parameter for distinguishing the two mesogenic structures. Our ML model enables automatic and systematic analysis of the mesogenic structures without prior knowledge, and thus can overcome the difficulty of manually determining the specific order parameter required for the classification of complex structures.

    DOI: 10.1038/s41598-019-51238-1

  • Theoretical study on optical properties of liquid crystalline Skyrmion lattice

    Junichi Fukuda, Slobodan Zumer

    Emerging Liquid Crystal Technologies XIV 2019 Emerging Liquid Crystal Technologies XIV   2019年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    A chiral liquid crystal sandwiched by two parallel plates has been shown to exhibit various exotic structures including a hexagonal lattice of Skyrmion excitations. Here we focus on the optical properties of a hexagonal Skyrmion lattice and present our theoretical studies based on direct numerical solving of Maxwell equations for light waves. Specifically, we discuss Kossel diagrams and optical microscope images of a hexagonal Skyrmion lattice and other structures resembling a thin slice of a bulk blue phase structure.

    DOI: 10.1117/12.2507520

  • Liquid-crystalline half-Skyrmion lattice spotted by Kossel diagrams 査読

    Junichi Fukuda, Andriy Nych, Uliana Ognysta, Žumer Slobodan, Igor Muševič

    Scientific reports   8 ( 1 )   2018年12月

     詳細を見る

    記述言語:英語  

    Skyrmions are swirl-like topological entities that have been shown to emerge in various condensed matter systems. Their identification has been carried out in different ways including scattering techniques and real-space observations. Here we show that Kossel diagrams can identify the formation of a hexagonal lattice of half-Skyrmions in a thin film of a chiral liquid crystal, in which case Kossel lines appear as hexagonally arranged circular arcs. Our experimental observations on a hexagonal lattice of half-Skyrmions and other defect structures resembling that of a bulk cholesteric blue phase are perfectly accounted for by numerical calculations and a theoretical argument attributing strong reflections yielding Kossel lines to guided mode resonances in the thin liquid crystal film. Our study demonstrates that a liquid crystal is a model system allowing the investigation of topological entities by various optical means, and also that Kossel techniques are applicable to the investigation of thin systems with non-trivial photonic band structures including topologically protected optical surface states.

    DOI: 10.1038/s41598-018-35514-0

  • Orientation of liquid crystalline blue phases on unidirectionally orienting surfaces 査読

    Misaki Takahashi, Takuma Ohkawa, Hiroyuki Yoshida, Jun-Ichi Fukuda, Hirostugu Kikuchi, Masanori Ozaki

    Journal of Physics D: Applied Physics   51 ( 10 )   104003   2018年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Liquid crystalline cholesteric blue phases (BPs) continue to attract interest due to their fast response times and quasi-polarization-independent phase modulation capabilities. Various approaches have recently been proposed to control the crystal orientation of BPs on substrates
    however, their basic orientation properties on standard, unidirectionally orienting alignment layers have not been investigated in detail. Through analysis of the azimuthal orientation of Kossel diagrams, we study the 3D crystal orientation of a BP material - with a phase sequence of cholesteric, BP I, and BP II - on unidirectionally orienting surfaces prepared using two methods: rubbing and photoalignment. BP II grown from the isotropic phase is sensitive to surface conditions, with different crystal planes orienting on the two substrates. On the other hand, strong thermal hysteresis is observed in BPs grown through a different liquid crystal phase, implying that the preceding structure determines the orientation. More specifically, the BP II-I transition is accompanied by a rotation of the crystal such that the crystal direction defined by certain low-value Miller indices transform into different directions, and within the allowed rotations, different azimuthal configurations are obtained in the same cell depending on the thermal process. Our findings demonstrate that, for the alignment control of BPs, the thermal process is as important as the properties of the alignment layer.

    DOI: 10.1088/1361-6463/aaaa4b

  • Development of coarse-grained liquid-crystal polymer model with efficient electrostatic interaction Toward molecular dynamics simulations of electroactive materials 査読

    Kenji Tagashira, Kazuaki Z. Takahashi, Junichi Fukuda, Takeshi Aoyagi

    Materials   11 ( 1 )   2018年1月

     詳細を見る

    記述言語:英語  

    Liquid-crystal polymers (LCPs) are well known materials for functional sensor and actuators, because of their high-responsiveness to an electric field. Owing to their complex physical nature, however, the prediction of the functions of LCPs is a challenge. To attack this problem from a molecular point of view, a simulation study is a promising approach. In this work, for future applications of molecular dynamics simulations to problems involving an electric field, we develop an LCP model which consists of coarse-grained mesogenic molecules and smeared charges. For the smearing function of the electrostatic force, the Gauss error function is introduced. This smearing is optimized to attain a reasonable accuracy for phase transition phenomena of liquid crystal while numerical instabilities arising from the singularity of the Coulomb potential are circumvented. For swelling systems, our LCP model exhibits the characteristics of both liquid crystals and unentangled polymer chains; orientational order of the mesogenic units and Rouse-like relaxation dynamics. Our coarse-grained LCP model successfully incorporates electric charges and dipoles and is therefore applicable to problems concerning an electric field.

    DOI: 10.3390/ma11010083

  • Three-dimensional crystal orientation of blue phase liquid crystals on surfaces

    H. Yoshida, M. Takahashi, T. Ohkawa, Junichi Fukuda, Hirotsugu Kikuchi, M. Ozaki

    Liquid Crystals XXII 2018 Liquid Crystals XXII   2018年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    Liquid crystalline cholesteric blue phases (BPs) are of high interest for tunable electro-optic applications owing to their fast response times and quasi-polarization-independent phase modulation capabilities. Various approaches have recently been proposed to control the crystal orientation of BPs on substrates, but their basic orientation properties on standard, unidirectionally orienting substrates had not been investigated in detail. Here, detailed studies have been made on the Kossel diagrams of BPs on unidirectionally orienting substrates to understand the three-dimensional crystal orientation of BPs. We find that BPs show strong thermal hysteresis and that the structure of the preceding phase determines the orientation of BPs. Specifically, the BP II-I transition is accompanied by a rotation of the crystal such that the crystal direction defined by certain low-value Miller indices transform into different directions, and within the allowed rotations, different azimuthal configurations are obtained in the same cell depending on the thermal process. Our findings demonstrate that, for the alignment control of BPs, the thermal process is as important as the properties of the alignment layer.

    DOI: 10.1117/12.2323159

  • Reflection spectra and near-field images of a liquid crystalline half-Skyrmion lattice 査読

    Jun-Ichi Fukuda, Slobodan Umer

    Optics Express   26 ( 2 )   1174 - 1184   2018年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically the optical properties of a hexagonal half-Skyrmion lattice exhibited by a highly chiral liquid crystal confined between two parallel plates. Our study focuses on the near and far-field reflection for normally incident light with di erent polarizations. We show that, when the wavelength of the incident light is longer than a threshold value, the reflectivity is almost insensitive to the polarization of the incident light, although the intensity profiles of the reflected light, in particular in the near-field regime, depend significantly on the polarization. The former property is attributable to the quasi two-dimensional nature of the half-Skyrmion lattice, that is, an almost uniform orientational order along the direction normal to the confining plates. Our results for the intensity of reflected light generated by evanescent as well as propagating contributions suggest that direct evidence of the formation and structure of half-Skyrmions could be provided by near-field optics with resolutions higher than that of conventional optical microscopy.

    DOI: 10.1364/OE.26.001174

  • Numerical calculation of Kossel diagrams of cholesteric blue phases

    Junichi Fukuda, Yasushi Okumura, Hirotsugu Kikuchi

    2018 Emerging Liquid Crystal Technologies XIII Emerging Liquid Crystal Technologies XIII   10555   2018年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    Kossel diagrams visualize the directions of strong Bragg reflections from a specimen with periodic ordering. They have played a pivotal role in the determination of the symmetry of cholesteric blue phases, and in the investigation of their structural changes under an electric field. In this work, we present direct numerical calculations of the Kossel diagrams of cholesteric blue phases by solving the Maxwell equations for the transmission and reflection of light incident upon a finite-thickness blue phase cell. Calculated Kossel diagrams are in good agreement with what is expected as a result of Bragg reflections, although some differences are present.

    DOI: 10.1117/12.2286290

  • Uncovering different states of topological defects in schlieren textures of a nematic liquid crystal 査読

    Takuya Ohzono, Kaoru Katoh, Chenguang Wang, Aiko Fukazawa, Shigehiro Yamaguchi, Jun-ichi Fukuda

    SCIENTIFIC REPORTS   7   2017年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Topological defects are ubiquitously found in physical systems and therefore have been an important research subject of not only condensed matter physics but also cosmology. However, their fine structures remain elusive because of the microscopic scales involved. In the case of a liquid crystal, optical microscopy, although routinely used for the identification of liquid crystal phases and associated defects, does not have resolution high enough to distinguish fine structures of topological defects. Here we show that polarised and fluorescence microscopy, with the aid of numerical calculations on the orientational order and resulting image distortions, can uncover the structural states of topological defects with strength m = +/- 1 in a thin cell of a nematic liquid crystal. Particularly, defects with m = +1 exhibit four different states arising from chiral symmetry breaking and up-down symmetry breaking. Our results demonstrate that optical microscopy is still a powerful tool to identify fine states of liquid crystalline defects.

    DOI: 10.1038/s41598-017-16967-1

  • Glycolipid-based nanostructures with thermal-phase transition behavior functioning as solubilizers and refolding accelerators for protein aggregates 査読

    N. Kameta, T. Matsuzawa, K. Yaoi, Junichi Fukuda, M. Masuda

    Soft Matter   13 ( 17 )   3084 - 3090   2017年1月

     詳細を見る

    記述言語:英語  

    The self-assembly of synthetic glycolipids produced nanostructures such as vesicles and nanotubes consisting of bilayer membranes, which underwent a gel-to-liquid crystalline thermal phase transition. Vesicles formed at temperatures above the thermal phase transition temperatures (Tg-l) could solubilize aggregates of denatured proteins by trapping them in the fluid bilayer membranes. Cooling to temperatures below Tg-l caused a morphological transformation into nanotubes that accompanied the thermal phase transition from the fluid to the solid state. This phenomenon allowed the trapped proteins to be quickly released into the bulk solution and simultaneously facilitated the refolding of the proteins. The refolding efficiency strongly depended on the electrostatic attraction between the bilayer membranes of the nanostructures and the proteins. Because of the long shape (>400 nm) of the nanotubes, simple membrane filtration through a pore size of 200 nm led to complete separation and recovery of the refolded proteins (3-9 nm sizes).

    DOI: 10.1039/c7sm00310b

  • Do small molecules assemble at topological defects of a liquid crystal?

    Junichi Fukuda

    2017 Emerging Liquid Crystal Technologies XII Conference, ELCT 2017 Emerging Liquid Crystal Technologies XII 2017   10125   2017年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    It is well known that topological defects of a liquid crystal can trap colloidal particles and polymers. However, it remains unclear whether low-molecular-weight (LMW) non-LC molecules can aggregate at topological defects, because entropy towards uniform distributions becomes more dominant for smaller molecules. We show by a simple theoretical argument that topological defects indeed give rise to non-uniform distributions of such LMW guest molecules. The relaxation of the high free energy density of topological defects by the presence of LMW guest molecules is strong enough to overcome the contribution of entropy. We briefly discuss the relevance of our theoretical arguments to experiments.

    DOI: 10.1117/12.2256541

  • Fluorescence microscopy reveals molecular localisation at line defects in nematic liquid crystals 査読

    Takuya Ohzono, Kaoru Katoh, Jun-ichi Fukuda

    SCIENTIFIC REPORTS   6   2016年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Topological defects easily form in liquid crystals (LCs) as a result of frustrations in spatially dependent anisotropic molecular ordering, and have been regarded as promising tools for facilitating manipulation of relatively large non-LC materials such as colloids. However, it remains unclear whether low-molecular-weight (LMW) impurities that do not aggregate or self-assemble in bulk LCs because of the dominance of entropy can localise at LC defects. Here, by fluorescence microscopy, we directly show the localisation of LMW molecules at the topological line defects of a nematic LC. It is theoretically explained that excess free energy density of nematic ordering at the defect core allows LMW solutes to accumulate at a non-negligible level overcoming the entropy leading to their uniform distributions. Our results demonstrate the usefulness of LC defects as a bottom-up field that enables micromanipulation of LMW molecules and realisation of transformable three-dimensional micro-architectures composed of versatile small functional molecules.

    DOI: 10.1038/srep36477

  • Bragg reflection band width and optical rotatory dispersion of cubic blue-phase liquid crystals 査読

    Hiroyuki Yoshida, Konkanok Anucha, Yasuhiro Ogawa, Yuto Kawata, Masanori Ozaki, Jun-ichi Fukuda, Hirotsugu Kikuchi

    PHYSICAL REVIEW E   94 ( 4 )   2016年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The Bragg reflection band width and optical rotatory dispersion of liquid crystalline cholesteric blue phases (BPs) I and II are compared by numerical simulations. Attention is paid to the wavelength regions for which the reflection bands with lowest photon energies appear, i.e., the [110] direction for BP I and the [100] direction for BP II. Finite difference time domain and 4 x 4 matrix calculations performed on the theoretical director tensor distribution of BPs with the same material parameters show that BP II, which has simple cubic symmetry, has a wider photonic band gap than BP I, which has body centered cubic symmetry, possibly due to the fact that the density of the double-twist cylinders in BP II are twice that in BP I. The theoretical results on the Bragg reflection band width are supported by reflectance measurements performed on BPs I and II for light incident along the [110] and [100] directions, respectively.

    DOI: 10.1103/PhysRevE.94.042703

  • Calculation of confocal microscope images of cholesteric blue phases

    Junichi Fukuda, Yasushi Okumura, Hirotsugu Kikuchi

    Emerging Liquid Crystal Technologies XI Emerging Liquid Crystal Technologies XI   9769   2016年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    Real-space images of bulk cholesteric blue phases (BPs) have been successfully obtained by confocal microscopy observations using structural color without doping fluorescent dye. However, theoretical interpretation of these images (for example, the understanding of the relation between intensity distribution and the ordering of BPs) remains challenging because typical lattice spacing of BPs is of the order of the wavelength of visible light, and therefore geometrical optics is entirely useless. In this work, we present a numerical approach to calculate the confocal images of BPs by solving the Maxwell equations. Calculated confocal images are consistent with experimental observations in terms of in-plane symmetry.

    DOI: 10.1117/12.2209210

  • Templated blue phases 査読

    Miha Ravnik, Junichi Fukuda

    Soft Matter   11 ( 43 )   8417 - 8425   2015年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Cholesteric blue phases of a chiral liquid crystal are interesting examples of self-organised three-dimensional nanostructures formed by soft matter. Recently it was demonstrated that a polymer matrix introduced by photopolymerization inside a bulk blue phase not only stabilises the host blue phase significantly, but also serves as a template for blue phase ordering. We show with numerical modelling that the transfer of the orientational order of the blue phase to the surfaces of the polymer matrix, together with the resulting surface anchoring, can account for the templating behaviour of the polymer matrix inducing the blue phase ordering of an achiral nematic liquid crystal. Furthermore, tailoring the anchoring conditions of the polymer matrix surfaces can bring about orientational ordering different from those of bulk blue phases, including an intertwined complex of the polymer matrix and topological line defects of orientational order. Optical Kerr response of templated blue phases is explored, finding large Kerr constants in the range of K = 2-10 × 10-9 m V-2 and notable dependence on the surface anchoring strength. More generally, the presented numerical approach is aimed to clarify the role and actions of templating polymer matrices in complex chiral nematic fluids, and further to help design novel template-based materials from chiral liquid crystals.

    DOI: 10.1039/c5sm01878a

  • Exotic Defect Structures and Their Optical Properties in a Strongly Confined Chiral Liquid Crystal 査読

    Jun-ichi Fukuda, Slobodan Zumer

    MOLECULAR CRYSTALS AND LIQUID CRYSTALS   594 ( 1 )   70 - 77   2014年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We numerically investigate structural and optical properties of a highly chiral liquid crystal when it is confined in a thin planar cell imposing strong homeotropic anchoring. Various stable exotic defect structures different from those of bulk cholesteric blue phases are found depending on temperature and cell thickness. We also study how a planar cell with these defect structures reflect and transmit incident light, paying particular attention to a structure with double-helix disclination lines and one similar to bulk BP II.

    DOI: 10.1080/15421406.2014.917474

  • Twist transition of nematic hyperbolic hedgehogs 査読

    Richard James, Jun-Ichi Fukuda

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   89 ( 4 )   2014年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Stability of an idealized hyperbolic hedgehog in a nematic liquid crystal against a twist transition is investigated by extending the methodology of Rüdinger and Stark [Liq. Cryst. 26, 753 (1999)LICRE60267-829210.1080/ 026782999204840], where the hedgehog is confined between two concentric spheres. In the ideal hyperbolic-hedgehog the molecular orientation is assumed to rotate proportionally with respect to the inclination angle, θ (and in the opposite sense). However, when splay, k11, and bend, k33, moduli differ this proportionality is lost and the liquid crystal deforms relative to the ideal with bend and splay. Although slight, these deformations are shown to significantly shift the transition if k11/k33 is small. By increasing the degree of confinement the twist transition can be inhibited, a characteristic both hyperbolic and radial hedgehogs have in common. The twist transition of a hyperbolic defect that accompanies a particle is found to be well predicted by the earlier stability analysis of a thick shell. © Published by the American Physical Society.

    DOI: 10.1103/PhysRevE.89.042501

  • Photonic band structure and transmission analysis of cholesteric blue phase II: electrostriction in the [100] direction 査読

    Yasuhiro Ogawa, Jun-ichi Fukuda, Hiroyuki Yoshida, Masanori Ozaki

    OPTICS EXPRESS   22 ( 4 )   3766 - 3772   2014年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The photonic band structure and transmission properties of a cholesteric blue phase II liquid crystal, which is elongated in the [100] direction by electrostriction, are analyzed by finite-difference time-domain method. The simple cubic lattice deforms into a tetragonal lattice under the influence of an electric field, resulting in a change of the photonic band structure. Moreover, we show that the circular polarization dependence of the transmittance spectrum changes in an electric field, a behavior that has yet to be observed in experiment. (C) 2014 Optical Society of America

    DOI: 10.1364/OE.22.003766

  • Interaction of small spherical particles in confined cholesteric liquid crystals 査読

    B. I. Lev, Jun-ichi Fukuda, O. M. Tovkach, S. B. Chernyshuk

    PHYSICAL REVIEW E   89 ( 1 )   2014年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The theory of the elastic interaction of spherical colloidal particles immersed into a confined cholesteric liquid crystal is proposed. The case of weak anchoring on the particle surfaces is considered. We derive a general expression for the energy of the interaction between small spherical particles (with diameter much smaller than the cholesteric pitch) suspended in a cholesteric confined by two parallel planes. The resulting form of the interaction energy has a more complex spatial pattern and energy versus distance dependence than that in nematic colloids. The absence of translational symmetry related to helical periodicity and local nematic ordering in cholesteric liquid crystals manifest themselves in the complex nature of the interaction maps.

    DOI: 10.1103/PhysRevE.89.012509

  • Simulation of the switching dynamics of a cholesteric blue phase cell by an inhomogeneous in-plane field 査読

    Jun-ichi Fukuda

    JAPANESE JOURNAL OF APPLIED PHYSICS   53 ( 1 )   2014年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    By numerical calculations based on a continuum theory, we investigate the dynamics of a cholesteric blue phase liquid crystal cell with comb-like electrodes generating an inhomogeneous in-plane electric field. We demonstrate that the cholesteric blue phase respond to the electric field depending sensitively on the local field strength; disclination lines inherent in cholesteric blue phases disappear under a strong field. We also show that the typical response time is much smaller than milliseconds (those of nematic cells) as shown experimentally. (C) 2014 The Japan Society of Applied Physics

    DOI: 10.7567/JJAP.53.010301

  • Peculiarity of the interaction of small particles in smectic liquid crystals 査読

    O. M. Tovkach, Jun-Ichi Fukuda, B. I. Lev

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   88 ( 5 )   2013年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate the peculiarity of the interaction between particles immersed into a smectic liquid crystal with a layered structure. Such a structure of a liquid crystal imposes restrictions on possible deformations of the layer displacement field. Previous studies neglect this fact and give improper results for the interaction potential within one molecular layer. The present paper shows that such restrictions yield an interaction potential substantially different from those of previous studies. Oscillatory behavior, which was not present in the potentials of previous studies, might give rise to superstructures of immersed particles with finite interparticle distance. © 2013 American Physical Society.

    DOI: 10.1103/PhysRevE.88.052502

  • Finite-difference time-domain analysis of cholesteric blue phase II using the Landau-de Gennes tensor order parameter model 査読

    Yasuhiro Ogawa, Jun-ichi Fukuda, Hiroyuki Yoshida, Masanori Ozaki

    OPTICS LETTERS   38 ( 17 )   3380 - 3383   2013年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We numerically calculated the photonic band structure of a cholesteric blue phase II (BPII) liquid crystal using two models, the tensor order parameter model and the double-twist cylinder (DTC) model. The tensor order parameter model was derived numerically from the Landau-de Gennes theory, whereas the DTC model simply assumed a three-dimensional stack of ordered cylinders. The two models yielded similar photonic band structures; however, the polarization dependence of the transmission spectrum through the (100) direction in BPII was different. The results from the tensor order parameter model gave a better qualitative agreement with experiments on the transmission spectrum. This demonstrates the importance of a precise orientation model in the analysis of the optical properties of cholesteric blue phases. (C) 2013 Optical Society of America

    DOI: 10.1364/OL.38.003380

  • Effect of anchoring energy and elastic anisotropy on spherical inclusions in a nematic liquid crystal 査読

    Richard James, Jun-ichi Fukuda

    PHYSICAL REVIEW E   88 ( 1 )   2013年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    This paper explores how pairs of spherical particles with homeotropic (normal) surface anchoring cluster when immersed in nematic liquid crystal. By means of the Landau-de Gennes continuum theory we calculate how the equilibrium separation of a particle pair depends on the anchoring energy at the particle surface and the elastic anisotropy of the liquid crystal. We find that, for modest to strong anchoring strengths, the particle separation depends linearly on the elastic anisotropy and the inverse of the anchoring strength. Thus, the anchoring strength can be estimated by measuring the particle-pair separation.

    DOI: 10.1103/PhysRevE.88.010501

  • Field-induced dynamics and structures in a cholesteric-blue-phase cell 査読

    Jun-ichi Fukuda, Slobodan Zumer

    PHYSICAL REVIEW E   87 ( 4 )   2013年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically the relaxational dynamics of the orientational order of a cholesteric blue phase (BP) in a planar cell enforcing normal alignment in response to the application and cessation of an external electric field. We focus on the cases where blue phase I (BP I) is stable in the bulk. We show how the reorganization processes of the network of disclinations depend on the field strength and the history of the application of the field. We also demonstrate that the relaxation processes following the cessation of the field are particularly complex and depend sensitively on the profile of the orientational order before the cessation of the field. DOI: 10.1103/PhysRevE.87.042506

    DOI: 10.1103/PhysRevE.87.042506

  • Theory and simulation of cholesteric blue phases Effect of the elastic constants on the stability of blue phases and the response of a blue phase cell to an electric field

    Junichi Fukuda

    Liquid Crystals XVI Liquid Crystals XVI   8475   2012年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    We present our recent theoretical and numerical studies concerning the properties of cholesteric blue phases (BPs). One is on the effect of the variation of the Frank elastic constants on the stability of BPs. Our study is based on a classical and well-known theory of Meiboom et al. that gave a rough estimate of the temperature range of stable BPs in the case of equal elastic constants. We extend it to take into account the difference of the elastic constants. We show that the stability of BPs is greatly enhanced when the bend elastic constant K33 is smaller, which agrees well with recent experiments. We also show that larger splay (K11) and twist (K 22) elastic constants are also favorable for the stability of BPs. The other subject of the present paper is the response of BPs in a parallel cell to an applied electric field. We carry out numerical calculations for the investigation the dynamics of orientational order and associated disclination lines. Our calculations are based on a Landau-de Gennes theory describing the orientational order of the liquid crystal by a second-rank tensor. Our preliminary calculations demonstrate that a non-uniform electric field induced by comb-like electrodes gives rise to non-trivial dynamics of disclination lines.

    DOI: 10.1117/12.929315

  • Transition of frustrated nematic order and fluctuation of topological defects in microwrinkle grooves 査読

    Takuya Ohzono, Junichi Fukuda

    Soft Matter   8 ( 45 )   11552 - 11556   2012年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We show that a nematic liquid crystal confined in sinusoidal microwrinkle grooves imposing antagonistic boundary conditions exhibits noteworthy structural transitions of nematic order and associated line defects under the variation of temperature (T). The defects also show unusual temperature-dependent fluctuations whose amplitude squared depends nonlinearly on T. The temperature dependence of the elastic constants of the liquid crystal and their ratio is responsible for these transitions and fluctuations. A variety of transformable defect structures with characteristic fluctuations will open up new possibilities for organizing and manipulating colloids and a liquid crystal confined in microwrinkle grooves could be a tangible one-dimensional model system to study the nature of fluctuations.

    DOI: 10.1039/c2sm26701b

  • Stability of cholesteric blue phases in the presence of a guest component 査読

    Jun-ichi Fukuda

    PHYSICAL REVIEW E   86 ( 4 )   2012年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate theoretically, with the aid of numerical calculations based on a Landau-de Gennes theory, how two cubic cholesteric blue phases of a chiral liquid crystal, BP I and BP II, are stabilized when a guest component, such as a polymer network, is introduced and replace energetically costly defect regions. We show that the temperature range of stable BP I is significantly widened by the guest component, while the stability of BP II is only modestly enhanced.

    DOI: 10.1103/PhysRevE.86.041704

  • ±1/2 wedge disclinations stabilized by a sinusoidal boundary in a thin hybrid nematic liquid-crystal film 査読

    Ohzono T, Fukuda J.-I, Suzuki K, Yamaguchi T

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   86 ( 3 )   2012年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    +/- 1/2 wedge disclinations stabilized by a sinusoidal boundary in a thin hybrid nematic liquid-crystal film
    As an interesting example of how geometry affects the formation of defects, we study the defect structures of a hybrid nematic liquid-crystal film in a wedge-shaped cell made up of sinusoidal microwrinkles and an elastomer sheet. When the cell thickness is larger than a threshold value h(c), +1/2 and -1/2 disclinations are simultaneously stabilized along concave grooves and convex crests, respectively. A simple theoretical analysis gives a good estimate of h(c). The disclinations also show alternating optical rotations resulting from the curved boundary and liquid-crystal elastic anisotropy.

    DOI: 10.1103/PhysRevE.86.030701

  • Confined colloidal blue phases with potential for photonics 査読

    Žumer Slobodan, Junichi Fukuda, Miha Ravnik

    Molecular Crystals and Liquid Crystals   561   107 - 114   2012年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We have recently demonstrated various quasi-2D disclination networks in blue phases confined to thin layers, ranging from rings, skyrmions, to double helices, which can provide arrays of trapping sites for an easy assembling of colloidal particles in complex 2D lattice structures. In this brief review, we summarize main findings of our phenomenological modeling combined with topology. Effects of confinement, particle sizes and anchoring are discussed. Quasi-2D colloidal crystals can be easily manipulated by external stimuli via affecting liquid crystal or colloidal particles and offer means for novel applications in photonics.

    DOI: 10.1080/15421406.2012.687143

  • Focal conics in a smectic-A liquid crystal in microwrinkle grooves 査読

    Takuya Ohzono, Yoshiko Takenaka, Junichi Fukuda

    Soft Matter   8 ( 24 )   6438 - 6444   2012年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Focal conic domains (FCDs) in smectic-A (SmA) liquid crystals (LCs) are a broad class of curvature defects in a layered system. Here, we report a regular array of FCDs in octylcyanobiphenyl in a SmA phase confined within sinusoidal microgrooves of microwrinkles with a specific periodicity. A semi-hybrid alignment is imposed by the air-LC interface (homeotropic) and the LC-curved-microwrinkle interface (unidirectional planar). The FCDs are periodically packed along the groove direction when the wrinkle wavelength is larger than a critical value of approximately 4 μm. The periodicity of the FCDs monotonically increases with increasing the wrinkle wavelength. From our optical observation, we propose an internal layer structure of the FCDs composed of a set of Dupin cyclides with the eccentricity of the basic ellipse being approximately 0.75.

    DOI: 10.1039/c2sm25416f

  • Simulation of a cholesteric blue phase in a thin cell Exotic defect structures and their response to an electric field

    Junichi Fukuda, Žumer Slobodan

    Emerging Liquid Crystal Technologies VII Emerging Liquid Crystal Technologies VII   8279   2012年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    We present our numerical attempts to simulate the structures of a cholesteric blue phase (BP) confined in a thin cell. Our simulations are based on a Landau-de Gennes theory describing the orientational order of the liquid crystal by a second-rank symmetric tensor. When the cell thickness is small enough, of the order of the lattice constant of the bulk BP a, various exotic defect structures that do not resemble those of bulk BPs are shown to be stable. They include a hexagonal lattice of Skyrmion excitations, and arrays of disclination lines in a double-helix form. We also show the dynamics of disclination lines in a thicker cell (∼ 2.6 a) under an applied electric field. The cell before the application of an electric field accommodates disclination lines of the form similar to that of bulk BP. The electric field alters their form in a non-trivial way depending on the field strength.

    DOI: 10.1117/12.912825

  • Erratum Stabilization of blue phases by the variation of elastic constants (Physical Review E - Statistical, Nonlinear, and Soft Matter Physics (2012) 85 (020701)) 査読

    Junichi Fukuda

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   85 ( 2 )   2012年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1103/PhysRevE.85.029903

  • Stabilization of blue phases by the variation of elastic constants (vol 85, 020701, 2012) 査読

    Jun-ichi Fukuda

    PHYSICAL REVIEW E   85 ( 2 )   2012年2月

     詳細を見る

    記述言語:英語  

    DOI: 10.1103/PhysRevE.85.029903

  • Stabilization of blue phases by the variation of elastic constants 査読

    Jun-ichi Fukuda

    PHYSICAL REVIEW E   85 ( 2 )   2012年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study theoretically the effect of the variation of the elastic constants on the stability of cholesteric blue phases (BPs). We demonstrate that the stability of BPs is greatly enhanced when the bend elastic constant K-33 is smaller, in agreement with recent experimental findings. Larger splay (K-11) and twist (K-22) elastic constants also stabilize BPs. Our argument sheds light on the subtle effect of the variation of the elastic constants on the stability of BPs, and could guide the synthesis of liquid crystals with a wider temperature range of stable BPs.

    DOI: 10.1103/PhysRevE.85.020701

  • Confining blue phase colloids to thin layers 査読

    Miha Ravnik, Junichi Fukuda, Julia M. Yeomans, Žumer Slobodan

    Soft Matter   7 ( 21 )   10144 - 10150   2011年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Colloidal assembly in strongly confined cholesteric structures is demonstrated using phenomenological modelling. Particle trapping sites and trapping potentials, which are intrinsically imposed by the strongly anisotropic orientational profile of the confined blue phases, are calculated. Locations of the trapping sites and profiles of the trapping potentials are shown to depend importantly on the particle size, and the array of trapping sites can even change symmetry. Trapping sites provide robust binding of various colloidal structures with binding energy of ∼100kT for ∼100 nm particles. Maximising the filling of the trapping sites by particles proves to lower the full free energy of the system, offering means for thermodynamic stabilisation of confined blue phases. Finally, we present formation of disclination cages, formed as a three-dimensional closed network of defect lines surrounding sufficiently large particles with strong homeotropic anchoring.

    DOI: 10.1039/c1sm05707c

  • Confined blue phases Trapping of colloidal particles in disclination superstructures

    Žumer Slobodan, Miha Ravnik, Junichi Fukuda

    Liquid Crystals XV Liquid Crystals XV   8114   2011年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    In confined blue phases numerous quasi 2D disclination networks ranging from rings to double helices can be stable. We have recently demonstrated how such networks act as arrays of trapping sites that can lead to easy assembling of colloidal particles in complex 2D lattice structures. In this short overview we summarize main results of our Landau - de Gennes modeling combined with topology that was proven to be useful in bulk blue phase colloids. Effects of confinement, particle anchoring, and particle sizes that can range from micron to nanometre scale are presented. Quasi 2D colloidal crystals that can be easily manipulated by external stimuli via affecting liquid crystal and/or colloidal particles are expected to have possible photonic applications.

    DOI: 10.1117/12.893160

  • Structural forces in liquid crystalline blue phases 査読

    Jun-ichi Fukuda, Slobodan Zumer

    PHYSICAL REVIEW E   84 ( 4 )   2011年10月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We show numerically that the interaction potential or force mediated by a liquid crystalline blue phase (BP) between two parallel plates exhibits oscillatory behavior with variation of the interplate distance, when the parallel plates impose strong normal anchoring. Its periodicity is approximately half of the unit-cell dimension of the bulk BP. The interaction arises from the deformation of the confined BP structure around the midplane of the system. The oscillatory interaction can be regarded as a clear manifestation of the BP ordering, because the cholesteric helical alignment adopted by a chiral liquid crystal cannot yield an oscillatory interaction.

    DOI: 10.1103/PhysRevE.84.040701

  • Interparticle force in nematic colloids: Comparison between experiment and theory 査読

    Takahiro Kishita, Noboru Kondo, Kenji Takahashi, Masatoshi Ichikawa, Jun-ichi Fukuda, Yasuyuki Kimura

    PHYSICAL REVIEW E   84 ( 2 )   2011年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We have studied the interparticle force between two colloidal particles in a nematic liquid crystal experimentally and theoretically. The force F was directly measured using dual-beam optical tweezers and was numerically calculated from the equilibrium tensor field around the particles. The dependence of F on the center-to-center distance R between the particles was studied not only for equal-sized particles but also for different-sized ones in various kinds of configurations and arrangements. The magnitude of F between different-sized particles in the dipole configuration depends on their relative arrangement. Both experimental and theoretical force curves are found to be in good agreement with each other. At large R, they also make agreement with those predicted by an electrostatic analogy of nematic field.

    DOI: 10.1103/PhysRevE.84.021704

  • Report on the 9th Soft Matter Forum Conference of the Japanese Liquid Crystal Society 査読

    Jun-ichi Fukuda

    Liquid Crystals Today   20 ( 2 )   68 - 70   2011年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1080/1358314X.2011.563979

  • Interaction of spherical colloidal particles in nematic media with degenerate planar anchoring 査読

    Mohammad Reza Mozaffari, Mehrtash Babadi, Junichi Fukuda, Mohammad Reza Ejtehadi

    Soft Matter   7 ( 3 )   1107 - 1113   2011年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The interaction between two spherical colloidal particles with degenerate planar anchoring in a nematic media is studied by numerically minimizing the bulk Landau-de Gennes and surface energy using a finite element method. We find that the energy achieves its global minimum when the particles are in close contact and forming an angle = 28°± 2 with respect to the bulk nematic director, in agreement with the experiments. Although the quadrupolar structure of the director field is preserved in the majority of configurations, we show that for smaller orientation angles and at smaller inter-particle separations, the axial symmetry of the topological defect-pairs is continuously broken, resulting in the emergence of an attractive interaction.

    DOI: 10.1039/c0sm00761g

  • Stabilization of a blue phase by a guest component: An approach based on a Landau-de Gennes theory 査読

    Jun-ichi Fukuda

    PHYSICAL REVIEW E   82 ( 6 )   2010年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We discuss, with the aid of numerical calculations based on a Landau-de Gennes theory, the stabilization of a blue phase in chiral liquid crystals by introducing a guest component. Our argument is based on a common speculation that cores of disclination lines with higher free-energy density are replaced by the guest component. We assume that the guest component forms sharp interfaces with the liquid crystal (strong segregation). We show that, by a suitable choice of materials with small interfacial tension, a guest component of volume fraction less than 10&#37; drastically increases the temperature range of thermodynamic stability of a blue phase, in agreement with experiments [Kikuchi et al., Nature Mater. 1, 64 (2002)].

    DOI: 10.1103/PhysRevE.82.061702

  • Cholesteric blue phases Effect of strong confinement 査読

    Junichi Fukuda, Žumer S.

    Liquid Crystals   37 ( 6-7 )   875 - 882   2010年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    After an overview of cholesteric blue phases, we review our recent numerical studies on possible defect structures when blue phase I (BP I) is confined in a thin cell composed of two parallel surfaces imposing homeotropic anchoring. The cell thickness is of the order of the unit cell dimension of the bulk cubic BP I. We find several structures of disclination lines which, to our knowledge, have never been discussed in the field of liquid crystals as equilibrium structures. Those structures include a parallel array of double helix disclination lines, and two parallel arrays of undulating disclination lines almost (but not exactly) perpendicular to each other. A first-order transition between those two structures is possible, and the similarity between them is discussed.

    DOI: 10.1080/02678292.2010.481909

  • Continuous transformation of a-1/2 wedge disclination line to a+1/2 one 査読

    Jun-ichi Fukuda

    PHYSICAL REVIEW E   81 ( 4 )   2010年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    It is known that, in the order-parameter space S-2/Z(2) (a typical example being a uniaxial nematic liquid crystal in three dimensions), a -1/2 wedge disclination line and a +1/2 one are topologically equivalent and can thus be transformed continuously into each other. Here we report the realization of this transformation in a simulation of a cholesteric blue phase under an electric field.

    DOI: 10.1103/PhysRevE.81.040701

  • Arrangement dependence of interparticle force in nematic colloids 査読

    Takahiro Kishita, Kenji Takahashi, Masatoshi Ichikawa, Jun-ichi Fukuda, Yasuyuki Kimura

    PHYSICAL REVIEW E   81 ( 1 )   2010年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We have experimentally and theoretically studied the interparticle force between two colloidal particles with different sizes accompanied by hyperbolic hedgehog defects in a nematic liquid crystal. The force f was directly measured using dual-beam optical tweezers and calculated theoretically from the equilibrium tensor field around the particles. The dependence of f on the center-to-center distance between particles of different sizes R is different from that for particles with the same size. The magnitude of f depends on the relative arrangement of the particles: f is larger when a defect between the particles belongs to the larger particle. From the theoretical calculation, the difference in f between the two arrangements, delta f, monotonically increases with increasing size difference. The difference delta f was experimentally and theoretically found to be proportional to R(-4.6) at large R. The obtained exponent is comparable to the exponent of -5 predicted by electrostatic analogy.

    DOI: 10.1103/PhysRevE.81.010701

  • Critical reexamination of Berreman's theory on surface anchoring 査読

    Junichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    Molecular Crystals and Liquid Crystals   516   12 - 25   2010年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We critically reexamine well-known Berreman's theory [Phys. Rev. Lett. 28, 1683 (1972)] on the anchoring of a nematic liquid crystal due to its elastic distortions induced by a sinusoidally grooved surface. We put emphasis on the effect of azimuthal distortions of the director n and the contribution of saddle-splay surface elasticity characterized by K24. We give a correct calculation of the anchoring energy and show that Berreman's theory gives a correct result only when K1=K2 and K24=0, where K1 and K2 are the splay and twist elastic constants, respectively. We also present our preliminary numerical attempts to evaluate the anchoring energy of a surface with square patterns and compare the anchoring energy calculated numerically with an analytical one obtained by a direct extension of our theoretical argument on one-dimensional parallel grooves.

    DOI: 10.1080/15421400903397058

  • Simulation of cholesteric blue phases using a Landau-de Gennes theory: Effect of an applied electric field 査読

    Jun-ichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    PHYSICAL REVIEW E   80 ( 3 )   2009年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically static and dynamic properties of cholesteric blue phases. Our study is based on a Landau-de Gennes theory describing the orientational order of a liquid crystal in terms of a second-rank tensor. To find the shape and size of the unit cell conforming to the minimum of the free energy, we let the geometrical parameters characterizing the unit cell relax in the course of the time evolution via a simple relaxational equation. We investigate the effect of an electric field on the structure of cholesteric blue phases. We study how the deformation of the unit cell in response to the electric field E depends on the strength and direction of the electric field and the original structure of cholesteric blue phases. Our results qualitatively agree with the experimental findings. Although in a weak field, the strain tensor is proportional to E(2) as previously argued, for a moderate field the distortion is no longer proportional to E(2) and can be even non-monotonic with respect to E(2). Furthermore, we investigate the kinetic processes of the deformation, rearrangement, and extinction of disclination lines under a strong electric field. We show that the kinetics of disclination lines is highly complicated and sensitively depends on the initial structure of blue phases, the direction of the electric field, and the sign of dielectric anisotropy epsilon(a). In most cases, a strong field aligns the liquid crystals in a uniform (positive epsilon(a)) or helical (negative epsilon(a)) manner without disclination lines. However, for negative epsilon(a) and the direction of the electric field parallel to the body diagonal of the unit cell, disclination lines do not disappear and form a two-dimensional hexagonal lattice.

    DOI: 10.1103/PhysRevE.80.031706

  • Confinement effect on the interaction between colloidal particles in a nematic liquid crystal: An analytical study 査読

    Jun-ichi Fukuda, Slobodan Zumer

    PHYSICAL REVIEW E   79 ( 4 )   2009年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Motivated by a recent experimental study on the interaction between colloidal particles in a confined nematic liquid crystal [M. Vilfan, N. Osterman, M. Copic, M. Ravnik, S. Zumer, J. Kotar, D. Babic, and I. Poberaj, Phys. Rev. Lett. 101, 237801 (2008)], we discuss in an analytical manner how the interaction potential U between spherical colloidal particles in a confined nematic cell behaves as a function of the interparticle distance r. We show that the short-range potential follows a power law U(r)similar to r(-5) as expected from the quadrupolar nature of the interaction, while the long-range potential is dominated by an exponential function U(r)similar to root d/r exp(-2 pi r/d), where d is the cell thickness. These two regimes are interchanged at r/d similar or equal to 0.8. This behavior of U(r) is in a good semiquantitative agreement with the experimental finding.

    DOI: 10.1103/PhysRevE.79.041703

  • Liquid Crystal Colloids: A Novel Composite Material Based on Liquid Crystals 査読

    Jun-ichi Fukuda

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   78 ( 4 )   2009年4月

     詳細を見る

    記述言語:英語  

    Liquid crystal colloids are composite materials made Lip of colloidal particles and liquid crystalline host fluids. After introducing, various Specific properties of liquid crystal collloids that are absent in conventional colloidal systems, we review our Studies, based mainly on computer simulations Using Landau-de Gennes theory, to elicudate those properties Of liquid crystal colloids. We first present Our attempts to investigate the orientational profiles and defect structures of a nematic liquid crystal around one colloidal particle. We successfully reproduce two configurations observed experimentally when strong homeotropic anchoring is imposed at the particle surface; one is a configuration with a hedgehog defect, and in the other, the particle is encircled by a ring defect referred to as a Saturn ring,. Next we focus on the interaction between particles mediated by the elastic distortions of the host nematic liquid crystal. We calculate the interaction between particle., carrying a hedgehog, and that between particles connected by a birefringent region called a bubble-gum. The properties of those interactions obtained numerically have been recently verified experimentally in a quantitative manner. We also review some of the important and attractive features of liquid Crystal colloids not mentioned in the main part of the present paper.

    DOI: 10.1143/JPSJ.78.041003

  • Consistent numerical evaluation of the anchoring energy of a grooved surface 査読

    Jun-ichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    PHYSICAL REVIEW E   79 ( 1 )   2009年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We evaluate the azimuthal anchoring energy of a grooved surface by calculating numerically the Frank elastic energy of a nematic cell composed of the grooved surface and a flat one with rigid azimuthal anchoring, where the director is fixed along the phi direction. We pay attention to the surface anchoring induced by elastic distortions of the director due to its contact with a nonflat surface, which impose local planar degenerate anchoring. Surface anchoring of this kind was analyzed analytically for shallow grooves by Berreman [Phys. Rev. Lett. 28, 1683 (1972)] and critically reexamined by the present authors [Phys. Rev. Lett. 98, 187803; 99, 139902(E) (2007)]. We consider two types of surface. one is a surface with one-dimensional sinusoidal parallel grooves, and the other is a surface with two-dimensional square patterns whose surface height is given by a sum of two sinusoidal functions with orthogonal wave vectors. The total energy is the sum of the anchoring energy and the twist energy in the bulk. For the calculation of the twist energy to be eliminated and the evaluation of the azimuthal-angle dependence of the anchoring energy, the "average" azimuthal angle at the bottom, phi(0), must be determined. We adopt two methods to determine phi(0). One is a simple extrapolation of the twist deformation in the bulk. The other relates phi(0) to the variation of the total Frank elastic energy with respect to phi. Our calculations indicate that both methods give essentially the same results, which indicates the consistency of those two methods. We also show that, for a surface with square patterns, the agreement between theory and numerical calculations is quite good even when the maximum of the surface slope is around 0.4, which theory assumes is much smaller than unity. When the surface slope is of order unity, the deviation of numerical results from theory crucially depends on the the surface elastic constant K(24).

    DOI: 10.1103/PhysRevE.79.011705

  • Nanostructured orientational surface patterns for functional LC alignment

    Hiroshi Yokoyama, Niitsuma Jun-ichi, Jin Seog Gwag, Junichi Fukuda, Makoto Yoneya

    16th International Display Workshops, IDW '09 IDW '09 - Proceedings of the 16th International Display Workshops   3   1647 - 1650   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    Orientational microscopic patterning of the alignment surface of liquid crystals has attracted rapidly increasing attention through the last decade as a novel approach to functionalization of otherwise inert liquid-crystal cell surfaces. Here, I will briefly review the underlying principle of the patterned alignment and also the development of fabrication processes. Recent results of photo-alignment and nanoimprint lithography technologies as applied to large-area processing are presented.

  • Simulation study of cholesteric blue phases under an electric field

    Junichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    16th International Display Workshops, IDW '09 IDW '09 - Proceedings of the 16th International Display Workshops   2   627 - 630   2009年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    We carry out a numerical study to investigate how a cholesteric blue phase responds to an electric field. Our study is based on a Landau-de Gennes continuum theory that describes the orientational order of a liquid crystal in terms of a second-rank tensor. Our numerical scheme allows the change in the size and shape of the unit cell in the course of relaxation to obtain an equilibrium profile of the orientational order. We find a distortion of the unit cell of blue phases under a weak field, which reproduces qualitatively the previous experimental findings. We also observe a rearrangement of disclination lines when a strong field is applied.

  • Anchoring of a nematic liquid crystal induced by surface grooves: A numerical study 査読

    Jun-ichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    PHYSICAL REVIEW E   77 ( 3 )   2008年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    To examine the anchoring energy of a surface with one-dimensional grooves of sinusoidal shape, we carry out numerical calculation of the Frank elastic energy of a nematic cell composed of such a grooved surface and a flat surface. We evaluate the anchoring energy of the grooved surface by carefully eliminating the contribution from a uniform twist deformation in the bulk. When qA less than or similar to 0.2, with q and A being the wave number and the amplitude of the surface groove, we find that the azimuthal-angle dependence of the calculated anchoring energy agrees perfectly with our previous analytical result under the assumption of qA << 1 [Fukuda et al., Phys. Rev. Lett. 98, 187803 (2007); 99, 139902 (E) ( 2007)]. Even when qA similar or equal to 0.6 or 1, we observe an unexpectedly good agreement between the calculated and the analytical anchoring energies, indicating the wide applicability of the analytical anchoring energy in spite of the assumption of qA << 1 in its derivation.

    DOI: 10.1103/PhysRevE.77.030701

  • Theory of anchoring on a two-dimensionally grooved surface 査読

    Jun-ichi Fukuda, Jin Seog Gwag, Makoto Yoneya, Hiroshi Yokoyama

    PHYSICAL REVIEW E   77 ( 1 )   2008年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate analytically the anchoring of a nematic liquid crystal on a two-dimensionally grooved surface of arbitrary shape, induced by the elastic distortions of a liquid crystal adjacent to the surface. Our theoretical framework applied to a surface with square grooves reveals that such a surface can exhibit bistable anchoring, while a direct extension of a well-known theory of Berreman [Phys. Rev. Lett. 28, 1683 (1972)] results in no azimuthal anchoring in the so-called one-constant case (K(1)=K(2)=K(3), with K(1), K(2), and K(3) being the splay, twist, and bend elastic constants, respectively). We show under the assumption of K(1)=K(2)=K that the direction of the bistable easy axes and the anchoring strength crucially depend on the ratios K(3)/K and K(24)/K, where K(24) is the saddle-splay surface elastic constant. To demonstrate the applicability of our theory to general cases and to elucidate the effect of surface shape and the elastic constants on the properties of surface anchoring, we also consider several specific cases of interest; one-dimensional grooves of arbitrary shape, rhombic grooves, and surfaces possessing 2N-fold symmetry, including hexagonal grooves, and show the following: (i) The rescaled anchoring energy f(phi)/f(pi/2) of one-dimensional grooves, with phi being the angle between the director n and the groove direction, is independent of the groove shape. (ii) Whether two diagonal axes of rhombic grooves can become easy axes depends sensitively on K(3)/K, K(24)/K and the angle alpha between the grooves. The angle alpha yielding the maximum anchoring strength for given groove pitch and amplitude depends again on K(3)/K and K(24)/K; in some cases alpha=0 (one-dimensional grooves), and in other cases alpha not equal 0, gives the maximum anchoring strength. Square grooves (alpha=pi/2) do not necessarily exhibit the largest anchoring strength. (iii) A surface possessing 2N-fold symmetry can yield N-stable azimuthal anchoring. However, when K(1)=K(2)=K(3) and N >= 3, azimuthal anchoring is totally absent irrespective of the value of K(24). The direction of the easy axes depends on K(3)/K, K(24)/K, and whether N is even or odd.

    DOI: 10.1103/PhysRevE.77.011702

  • Configuration of a chiral smectic-C film with a circular inclusion 査読

    J. Fukuda

    EUROPEAN PHYSICAL JOURNAL E   24 ( 1 )   91 - 98   2007年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    It was shown experimentally (P.V. Dolganov et al., Europhys. Lett. 76, 250 (2006)) and by numerical calculations (C. Bohley, R. Stannarius, Eur. Phys. J. E 23, 25 (2007)) that the c-director profile of a two-dimensional chiral smectic-C (SmC) film around a circular inclusion adopts dipolar rather than quadrupolar configuration observed in achiral SmC films. We give an analytical argument on how spontaneous bend inherent in chiral SmC liquid crystals influences the configuration of a SmC liquid crystal film around a circular inclusion imposing tangential anchoring. We find how the angle alpha between two surface defects seen from the center of the inclusion depends on the radius of the inclusion R and the strength of the spontaneous bend q . We show, however, that the contribution of the spontaneous bend to the free energy suffers from mathematical ambiguity; it depends on the mathematical treatment of the outer boundary even when it is at infinity. This might indicate that the shape as well as the treatment of the outer boundary of the film can significantly influence the equilibrium configuration of the c -director and the position of the surface defects.

    DOI: 10.1140/epje/i2007-10216-2

  • Surface-Groove-induced azimuthal anchoring of a nematic liquid crystal: Berreman's model reexamined (vol 98, pg 187803, 2007) 査読

    Jun-Ichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    PHYSICAL REVIEW LETTERS   99 ( 13 )   2007年9月

     詳細を見る

    記述言語:英語  

    DOI: 10.1103/PhysRevLett.99.139902

  • In-plane bistable nematic liquid crystal devices based on nanoimprinted surface relief 査読

    Jin Seog Gwag, Jun-ichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    APPLIED PHYSICS LETTERS   91 ( 7 )   2007年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The authors present a bistable nematic device, using a fourfold symmetrical bidirection nanometer-scale surface grating fabricated by the nanoimprinting lithography. The bistability is achieved by a composite action between two orthogonal surface undulations, which tend to stabilize the nematic director along either of the two diagonal axes. The switching between the bistable states is easily driven by orthogonal in-plane electric fields. A recent model of groove-induced surface anchoring due to Fukuda [Phys. Rev. Lett. 98, 187803 (2007)] accounts for the azimuthal bistability in the present system. (C) 2007 American Institute of Physics.

    DOI: 10.1063/1.2769946

  • Effect of an external field on the director profile of a nematic liquid crystal around a spherical particle 査読

    Junichi Fukuda, Hiroshi Yokoyama

    Molecular Crystals and Liquid Crystals   475 ( 1 )   165 - 172   2007年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In our previous study we have demonstrated that an adaptive mesh refinement scheme can be effectively used to investigate the orientation profiles of a nematic liquid crystal around a spherical particle when the characteristic size of the defect core is much smaller than the particle radius. We have also shown that the dynamics of a nematic liquid crystal can be properly treated to reproduce the experimentally observed structural transition from the hedgehog to the Saturn ring configuration induced by an external field. As a preliminary study for the quantitative investigation of this transition, we study in this article how the choice of the criterion for mesh refinement/unrefinement influences the stability of the hedgehog under an external field in our numerical system. The severer is the criterion for mesh refinement to produce a larger number of fine grids, the weaker field can induce the transition. Nevertheless, the dependence of the critical field strength on the criterion for mesh refinement is weak and the criterion can be systematically controlled. Therefore our numerical scheme is shown to be safely applied to the quantitative study on the stability of the hedgehog configuration under an external field.

    DOI: 10.1080/15421400701675366

  • Azimuthal nematic bistability at nanoimprinted surface groove

    Jin Seog Gwag, Junichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    14th International Display Workshops, IDW '07 IDW '07 - Proceedings of the 14th International Display Workshops   2   405 - 408   2007年

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    Azimuthal nematic bistability was induced by a composition action between two azimuthally orthogonal anchoring energies which were led by the combination of a nanoimprinted groove and a mechanical rubbing. The azimuthal easy directions can be controlled by the modulation of groove pitch and rubbing conditions. Fukuda's model is used to express surface anchoring of nematic liquid crystal in surface groove.

  • Stability of the director profile of a nematic liquid crystal around a spherical particle under an external field 査読

    J. Fukuda, H. Yokoyama

    EUROPEAN PHYSICAL JOURNAL E   21 ( 4 )   341 - 347   2006年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study numerically the effect of an external magnetic or electric field on the director profiles of a nematic liquid crystal around a spherical particle. We pay particular attention to the stability of a hyperbolic hedgehog defect accompanying the particle, which transforms into a Saturn-ring defect encircling the particle under a sufficiently strong external field. We focus on the particle size dependence of the two important threshold field strengths: the "thermodynamic-transition" field strength H-1 at which the hedgehog and the Saturn-ring configurations have the equal free energy, and the critical field strength H-2 at which the hedgehog loses its (meta)stability. Our numerical results demonstrate that while H-1 is non-monotonically dependent on the particle radius R-0, H-2 monotonically increases with R-0 and the dependence of H-2 is weak for large R-0. The non-monotonic dependence of H-1 on R-0 can be explained by comparing the energies of the two configurations and assuming the dependence of those energies on a rescaled field. A crude argument of the energetics of a hyperbolic hedgehog defect under an external field shows that for an asymptotically large R-0 the critical field strength is independent of R-0, which agrees with our numerical finding.

    DOI: 10.1140/epje/i2006-10072-6

  • Numerical treatment of the dynamics of a conserved order parameter in the presence of walls 査読

    Junichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   73 ( 6 )   2006年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We discuss how the diffusive dynamics of a conserved order parameter should be numerically treated when impenetrable wall surfaces are present and interact with the degrees of freedom characterized by the order parameter. We derive the discretization scheme for the dynamics, paying particular attention to the conservation of the order parameter in the strict numerical sense. The discretized chemical potential, or the functional derivative of the free energy, contains a surface contribution inversely proportional to the grid spacing Δz, which was proposed heuristically in a recent paper of Henderson and Clarke [Macromol. Theory Simul. 14, 435 (2005)]. Although apparently that surface contribution diverges in the continuum limit Δz→0, we can show, by an analytic argument and numerical calculations, that this divergence does not yield any anomalies, and that our discretization scheme is well defined in this limit. We also discuss the correspondence of our treatment to the model proposed by Puri and Binder [Phys. Rev. A 46, R4487 (1992)] extensively used for the present problem.

    DOI: 10.1103/PhysRevE.73.066706

  • Effect of a hydrodynamic flow on the orientation profiles of a nematic liquid crystal around a spherical particle 査読

    Makoto Yoneya, Junichi Fukuda, Hiroshi Yokoyama, Holger Stark

    Molecular Crystals and Liquid Crystals   435   2005年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study the effect of a hydrodynamic flow on the orientational configuration of a nematic liquid crystal around a spherical particle imposing rigid normal anchoring. We discuss the cases of large Ericksen numbers (characterizing the ratio of viscous force to the elastic force), where strong elastic deformation by the flow is expected. We assume the Stokes flow profile and deal with a simplified dynamic equation of the orientational order parameter of a second-rank tensor Qαβ. We consider the cases where a particle accompanying a hyperbolic hedgehog or a Saturn ring is subjected to a flow along the axis of rotational symmetry. In both cases the orientation profiles exhibit considerable deformation by a flow.

    DOI: 10.1080/15421400590956009

  • Interaction between particles in a nematic liquid crystal Numerical study using the Landau-de Gennes continuum theory 査読

    Junichi Fukuda, Hiroshi Yokoyama, Makoto Yoneya, Holger Stark

    Molecular Crystals and Liquid Crystals   435   2005年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study numerically the interaction between particles in a nematic liquid crystal mediated by its elastic distortions with the aid of the Landau-de Gennes continuum theory. We consider the cases where two particles impose rigid normal anchoring on their surfaces and are accompanied by a hyperbolic hedgehog defect. As a function of the distance between the centers of the particles D, we evaluate the force f acting on the particles by integrating the stress tensor. The result is well described by a power law f α D-x. When the "dipoles", composed of a particle and a hyperbolic hedgehog, are in parallel directions, the interaction is attractive and the exponent is x ≃ 4, consistent with the experimental observations together with the theoretical expectation of the dipole-dipole interaction. For antiparallel dipoles, repulsive interaction is observed and x ≃ 3.6, slightly stronger than the dipole-dipole interaction.

    DOI: 10.1080/15421400590956045

  • Friction drag of a spherical particle in a liquid crystal above the isotropic-nematic transition 査読

    Jun-Ichi Fukuda, Holger Stark, Hiroshi Yokoyama

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   72 ( 2 )   2005年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study the friction drag of a spherical particle in the isotropic phase of a nematic liquid crystal close to the isotropic-nematic transition point. To describe the orientational order in the liquid crystal, the second-rank tensor order parameter Qαβ is employed. We solve the hydrodynamic equations for Qαβ and the fluid velocity υ in order to determine the friction drag. In our discussion of the friction drag, we concentrate on four parameters: the temperature, the surface order parameter, the particle radius, and the Ericksen number Er (characterizing the ratio of the viscous force to the elastic force). The temperature dependence of the friction drag agrees well with experiments that show an increasing friction drag when the isotropic-nematic phase transition is approached from above. Furthermore the friction drag increases with the surface order parameter due to the more pronounced surface nematic layer, and for larger particles it is less affected by this layer. Finally, we observe that in the range of Er we study, the friction drag is almost independent of Er although flow-induced order occurs for sufficiently large Er and surface order parameter. © 2005 The American Physical Society.

    DOI: 10.1103/PhysRevE.72.021701

  • Director configuration of a nematic liquid crystal around a spherical particle Numerical analysis using adaptive mesh refinement 査読

    Junichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama

    Molecular Crystals and Liquid Crystals   413   2004年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically the orientational configuration of a nematic liquid crystal around a spherical particle. The use of adaptive mesh refinement scheme proves quite useful to overcome the numerical difficulty arising from large scale difference between a particle and a topological defect. Our scheme reproduces successfully the hedgehog and the Saturn ring configurations that have been observed experimentally. To demonstrate that dynamical behaviors can also be investigated using our scheme, we present a simulation result which exhibits a transition from a hedgehog to a Saturn ring under the application of an external field.

    DOI: 10.1080/15421400490437141

  • Interaction between spherical particles in a deformed liquid crystal 査読

    Junichi Fukuda, Keiko M. Aoki, Bohdan I. Lev, Hiroshi Yokoyama

    Molecular Crystals and Liquid Crystals   413   2004年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study how the initial deformation of a nematic liquid crystal affects the interaction between particles mediated by the elastic deformation of a nematic liquid crystal. We calculate the interaction energy between particles in a hybrid nematic cell, homeotropic on the surface of one confining plate and tangential (director can rotate freely) on the other. We find an analytic form of the interaction energy in the case of weak anchoring on the surface of the particle. This interaction energy can be non-monotonic and have a minimum in its landscape, which makes a clear contrast to that in a uniform nematic liquid crystal.

    DOI: 10.1080/15421400490437132

  • Numerical investigation of liquid crystal colloids using a continuum description 査読

    Junichi Fukuda, Makoto Yoneya, Hiroshi Yokoyama, Holger Stark

    Colloids and Surfaces B: Biointerfaces   38 ( 3-4 SPEC. ISS. )   143 - 147   2004年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically the configuration of a nematic liquid crystal around two spherical particles. For the description of the orientational order of a nematic liquid crystal, we adopt a Landau-de Gennes continuum theory in terms of a second-rank tensor order parameter Qij together with the use of bispherical coordinates to describe the geometry of the system with two spherical particles. Above but close to the nematic-isotropic transition point, we observe capillary condensation of a nematic liquid crystal between the two particles under appropriate conditions. Below the transition point where liquid crystals possess nematic order, a point-like defect called a hyperbolic hedgehog appears close to a particle when strong normal anchoring is imposed. With the aid of an adaptive mesh refinement scheme to achieve sufficient numerical resolution to describe topological defects, we present our numerical results showing how the orientation profile of a nematic liquid crystal is distorted when the distance between two particles is small enough.

    DOI: 10.1016/j.colsurfb.2004.02.019

  • Dynamics of a nematic liquid crystal around a spherical particle 査読

    J Fukuda, H Stark, M Yoneya, H Yokoyama

    JOURNAL OF PHYSICS-CONDENSED MATTER   16 ( 19 )   S1957 - S1968   2004年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present the results of our numerical calculations that focus on the dynamics of a nematic liquid crystal around a spherical particle imposing strong homeotropic anchoring at the surface. The first part of this article is devoted to the discussion of the effect of an external magnetic or electric field on the director configuration of a nematic liquid crystal. With the aid of an adaptive mesh refinement scheme, together with the tensor description of the orientational order, for the first time in numerical calculations we successfully reproduce the transition from a hyperbolic hedgehog defect to a Saturn ring defect, which was observed in a recent experiment. We also find that the trajectories of the defect core sensitively depend on the field strength. In the second part we investigate how a hydrodynamic flow influences the orientational order of a nematic liquid crystal around a particle carrying a hyperbolic hedgehog defect. We observe that for an intermediate Ericksen number, which characterizes the ratio of the viscous force to the elastic force of a nematic liquid crystal, the liquid crystal is strongly convected by the flow, which results in a considerable elastic distortion.

    DOI: 10.1088/0953-8984/16/19/008

  • Nematic wetting layers in liquid crystal colloids 査読

    H Stark, J Fukuda, H Yokoyama

    JOURNAL OF PHYSICS-CONDENSED MATTER   16 ( 19 )   S1911 - S1919   2004年5月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We first review the method of treating nematic wetting of planar surfaces following the approach introduced by Sheng. We present a phase diagram, which in the present form we have not found in the original literature. Then we consider spherical geometries of arbitrary radii, such as colloidal particles, and introduce an appropriate method for handling wetting in curved geometries. We find that a prewetting transition for high curvatures or small particle radii no longer occurs.

    DOI: 10.1088/0953-8984/16/19/004

  • Configuration of nematic liquid crystals around particles under external fields

    Junichi Fukuda, Holger Stark, Makoto Yoneya, Hiroshi Yokoyama

    3rd International Symposium on Slow Dynamics in Complex Systems Slow Dynamics in Complex Systems 3rd International Symposium on Slow Dynamics in Complex Systems   146 - 147   2004年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(その他学術会議資料等)  

    We present the results of our numerical attempts to simulate the configuration of a nematic liquid crystal around a spherical particle. We focus on the effect of an external field, such as a magnetic field or a flow field, on the director configuration and the topological defects accompanied by the particles. The use of adaptive mesh refinement together with a tensor order parameter for the description of the orientational order makes it feasible to tract the dynamics of a nematic liquid crystal without any special treatment of the topological defects.

    DOI: 10.1063/1.1764096

  • Wetting of a spherical particle by a nematic liquid crystal 査読

    Jun-Ichi Fukuda, Holger Stark, Hiroshi Yokoyama

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   69 ( 2 )   1 - 21714   2004年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The phenomena of wetting of a spherical particle by a nematic liquid crystal was studied. The investigation is based on Landau-de Gennes free energy formulated in terms of second-rank nematic order parameter. It was observed that the prewetting line ends at a critical point. It was found that the splay deformations around the particle significantly influence nematic wetting of curved surfaces.

    DOI: 10.1103/PhysRevE.69.021714

  • Nematic liquid crystal around a spherical particle: Investigation of the defect structure and its stability using adaptive mesh refinement 査読

    J Fukuda, M Yoneya, H Yokoyama

    EUROPEAN PHYSICAL JOURNAL E   13 ( 1 )   87 - 98   2004年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate the orientation profile and the structure of topological defects of a nematic liquid crystal around a spherical particle using an adaptive mesh refinement scheme developed by us previously. The previous work [J. Fukuda et al., Phys. Rev. E 65, 041709 (2002)] was devoted to the investigation of the fine structure of a hyperbolic hedgehog defect that the particle accompanies and in this paper we present the equilibrium profile of the Saturn ring configuration. The radius of the Saturn ring r(d) in units of the particle radius R-0 increases weakly with the increase of xi, the ratio of the nematic coherence length to R-0. Next we discuss the energetic stability of a hedgehog and a Saturn ring. The use of adaptive mesh refinement scheme together with a tensor orientational order parameter Q(alphabeta) allows us to calculate the elastic energy of a nematic liquid crystal without any assumption of the structure and the energy of the defect core as in the previous similar studies. The reduced free energy of a nematic liquid crystal, (F) over bar = F/L1R0, with L-1 being the elastic constant, is almost independent of xi in the hedgehog configuration, while it shows a logarithmic dependence in the Saturn ring configuration. This result clearly indicates that the energetic stability of a hedgehog to a Saturn ring for a large particle is definitely attributed to the large defect energy of the Saturn ring with a large radius.

    DOI: 10.1140/epje/e2004-00043-2

  • Hexagonal defect array formed under steady shear flow in water-in-cholesteric liquid crystal emulsions 査読

    M Yada, J Fukuda, J Yamamoto, H Yokoyama

    RHEOLOGICA ACTA   42 ( 6 )   578 - 584   2003年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The relation between the liquid crystalline textures and the steady shear viscosity has been investigated in cholesteric emulsions, composed of water, surfactants, and cholesteric liquid crystals. Both at the substrate surface and at the surfactant-coated droplet surface, a homeotropic anchoring is enforced to the adjacent liquid crystal. Under a steady shear flow with the shear rate below 100 s(-1), we observed that point defects spontaneously appear, and tend to adopt a regular hexagonal arrangement in the low shear-rate range of 1-20 s(-1). In viscosity measurements, the shear-thinning behavior was found, showing a clear correspondence to the texture change. We estimated the height of point defects in the hexagonal array from the viscosity increase in the shear-thinning, assuming that the shear-thinning behavior is caused by the reduction of the effective gap between cone and plate, owing to the presence of the hexagonal array anchored on the plate. The relation between the estimated height and the measured lateral size of point defects agreed with that of the quadrilateral array, which is formed after termination of the shear. This agreement informs that the shape of a point defect is preserved in both defect arrays, independently of shearing conditions.

    DOI: 10.1007/s00397-003-0314-y

  • Effect of confining walls on the interaction between particles in a nematic liquid crystal 査読

    J Fukuda, BI Lev, H Yokoyama

    JOURNAL OF PHYSICS-CONDENSED MATTER   15 ( 23 )   3841 - 3854   2003年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate theoretically how the confining walls of a nematic cell affect the interaction of particles mediated by the elastic deformation of a nematic liquid crystal: We consider the case where strong homeotropic or planar anchoring is imposed on the flat parallel walls so that the director on the wall surfaces is fixed and uniform alignment is achieved in the bulk. This set-up is more realistic experimentally than any other previous theoretical studies concerning the elastic-deformation-mediated interactions that,assume an infinite medium. When the anchoring on the particle surfaces is weak, an exact expression of the interaction between two particles can be-obtained. The two-body interaction can be regarded as the interaction between one particle. and an infinite array of 'mirror images' of the other particle. We also obtain the 'self-energy' of one particle, the interaction of a particle with confining walls,, which is interpreted along the same way as the interaction of one particle with its mirror images. We show that the walls play a different role in homeotropic and planar cells, which is attributed to the difference in the symmetry of the cells. We also. present the landscapes of the, interaction energy when one particle is fixed, and demonstrate that the interaction is sensitively dependent on the fixed particle as well as the interparticle distance.

    DOI: 10.1088/0953-8984/15/23/301

  • Interaction of particles in a deformed nematic liquid crystal 査読

    J Fukuda, BI Lev, KM Aoki, H Yokoyama

    PHYSICAL REVIEW E   66 ( 5 )   2002年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate how the interaction of particles mediated by an elastic deformation of a nematic liquid crystal is influenced by the initial deformation of the director field. To this end, we calculate the interaction energy between particles in a nematic cell with hybrid boundary conditions, homeotropic on the surface of one confining plate and planar on the other. We find an analytic form of the interaction energy in the case of weak anchoring on the surface of the particle. This interaction energy sensitively depends on the position of the two particles as well as the interparticle distance and can be nonmonotonic with a minimum in its landscape. This nontrivial energy landscape might lead to a chainlike superstructure of particles.

    DOI: 10.1103/PhysRevE.66.051711

  • Stability of a hyperbolic disclination ring in a nematic liquid crystal 査読

    J Fukuda, H Yokoyama

    PHYSICAL REVIEW E   66 ( 1 )   2002年7月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The stability of a hyperbolic disclination ring in a nematic liquid crystal is considered by extending the argument for a radial disclination ring due to Mori and Nakanishi. The ring configuration is indeed stable in the presence of the saddle-splay elasticity (characterized by K-24). The ring radius is estimated to be asimilar to2.9r(c), with r(c) being the core radius when K(24)similar or equal toK/2, where K is the Frank elastic constant in the one-constant approximation.

    DOI: 10.1103/PhysRevE.66.012703

  • Free energy of rigid rods: Contribution of rotational entropy to Frank elasticity 査読

    J Fukuda, H Yokoyama

    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN   71 ( 6 )   1463 - 1470   2002年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We apply the density functional formalism developed by the present authors [J. Fukuda and H. Yokoyama: J. Chem. Phys. 115 (2001) 4930] for the calculation of the free energy of rigid rods as a functional of the compositional scalar order parameter 0 and the orientational order parameter of second-rank tensor Q(ij) We model rigid rods as semiflexible wormlike chains with infinite bending elasticity and the exact expression for the entropic part of the free energy up to the second order in the gradients can be obtained. Discussion is devoted to the contribution of rotational entropy to Frank elasticity. Although none of the previous molecular theories for the Frank elasticity of liquid crystals has taken rotational entropy into account, our results indicate that rotational entropy can give a non-negligible contribution to Frank elasticity.

    DOI: 10.1143/JPSJ.71.1463

  • Defect structure of a nematic liquid crystal around a spherical particle: Adaptive mesh refinement approach 査読

    J Fukuda, M Yoneya, H Yokoyama

    PHYSICAL REVIEW E   65 ( 4 )   2002年4月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate numerically the structure of topological defects close to a spherical particle immersed in a uniformly aligned nematic liquid crystal. To this end we have implemented an adaptive mesh refinement scheme in an axi-symmetric three-dimensional system, which makes it feasible to take into account properly the large length scale difference between the particle and the topological defects. The adaptive mesh refinement scheme proves to be quite efficient and useful in the investigation of not only the macroscopic properties such as the defect position but also the fine structure of defects. It can be shown that a hyperbolic hedgehog that accompanies a particle with strong homeotropic anchoring takes the structure of a ring.

    DOI: 10.1103/PhysRevE.65.041709

  • Interaction of foreign macroparticles in a cholesteric liquid crystal 査読

    J Fukuda, BI Lev, H Yokoyama

    PHYSICAL REVIEW E   65 ( 3 )   2002年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We calculate the interaction energy between spherical macroparticles immersed in a cholesteric liquid crystal due to the elastic deformation of the director field. We assume weak anchoring on the surface of the macroparticles and obtain the expression of the interaction energy that is valid for particle radius and interparticle distance sufficiently smaller than the cholesteric pitch. The resultant form of the interaction energy is more complex than that in a nematic liquid crystal. One of the characteristics is its dependence on the particle position as well as the interparticle distance, which arises from the intrinsic structure of a cholesteric liquid crystal, i.e., the absence of translational symmetry due to helical periodicity and local nematic ordering whose orientation depends on the position.

    DOI: 10.1103/PhysRevE.65.031710

  • Calculation of the free energy of polymeric systems in terms of compositional and orientational order parameters 査読

    J Fukuda, H Yokoyama

    JOURNAL OF CHEMICAL PHYSICS   115 ( 10 )   4930 - 4937   2001年9月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We present a general framework for the calculation of the free energy functional of inhomogeneous polymeric systems in terms of the compositional scalar order parameter phi and the orientational order parameters of second-rank tensor Q(ij). Our formalism is a straightforward extension of the density functional theory developed by Tang and Freed [J. Chem. Phys. 94, 1572 (1991)] and the contribution of the conformational entropy is given in terms of the gradient expansion. As a demonstration, we give an exact expression for the free energy of Gaussian chains up to second order in the gradients. (C) 2001 American Institute of Physics.

    DOI: 10.1063/1.1395561

  • Director configuration and dynamics of a nematic liquid crystal around a two-dimensional spherical particle: Numerical analysis using adaptive grids 査読

    J Fukuda, H Yokoyama

    EUROPEAN PHYSICAL JOURNAL E   4 ( 3 )   389 - 396   2001年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We study numerically the director and orientational order parameter configurations in a nematic liquid crystal around a two-dimensional spherical particle on the basis of the tensor order parameter formalism. To properly account for the large length scale difference between the particle and the accompanying orientational defect, we devise an adaptive grid scheme in which the lattice spacing is automatically and locally adjusted. in response to the spatial gradient of the orientational order parameter. This adaptive grid scheme is useful in studying dynamical as well as static orientational structures. We present a simulation result which shows how a hedgehog defect of topological charge -1 becomes unstable in two dimensions, and splits into a defect pair of topological charge -1/2, located symmetrically around the particle.

    DOI: 10.1007/s101890170121

  • Frank elasticity revisited Contribution of rotational entropy 査読

    Junichi Fukuda, Hiroshi Yokoyama

    Molecular Crystals and Liquid Crystals   366   151 - 156   2001年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In previous molecular theories of nematic liquid crystals, rotational entropy, or the entropy loss due to molecular alignment, has been believed to make no contribution to Frank elasticity. We show that this is not true, using a field-theoretical method developed in polymer physics. We also give an exact expression of the contribution of rotational entropy to Frank elasticity for rod-like liquid crystals in terms of the orientational tensor order parameter.

    DOI: 10.1080/10587250108023957

  • Phase separation kinetics of main-chain liquid crystalline polymers 査読

    Junichi Fukuda

    Molecular Crystals and Liquid Crystals   366   901 - 908   2001年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate phase separation kinetics of main-chain liquid crystalline polymers (LCP's) by numerical calculations based on a continuum description. We introduce two order parameters, the density and the orientational order of LCP's and construct a set of time-dependent Ginzburg-Landau equations to describe the dynamics of these two order parameters. We show that the morphology of the phase-separated system is crucially influenced by the coupling between the density and the orientational order which appears in the kinetics as well as in the free energy.

    DOI: 10.1080/10587250108024033

  • Phase separation kinetics of liquid crystalline polymers: Effect of orientational order 査読

    J Fukuda

    PHYSICAL REVIEW E   59 ( 3 )   3275 - 3288   1999年3月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Phase separation kinetics of main-chain liquid crystalline polymers (LCP's) is investigated by numerically solving time-dependent Ginzburg-Landau equations for the compositional order parameter phi and the orientational order parameter S-ij. The kinetic coefficients are evaluated by using the biased reptation model with a microscopic model of wormlike chains. In numerical simulations we find the formation of a percolated network structure rich in LCP's that resembles that observed in experiments. In our kinetic equations the coupling between compositional order and orientational order appears in (i) the presence of the off-diagonal kinetic coefficient Lambda(phi S) and (ii) the dependence of the kinetic coefficients on S-ij (LCP's tend to diffuse parallel to the nematic orientation). We show by a linear analysis of the growing modes that the presence of Lambda(phi S) suppresses the growth of the compositional order in the early stage. We also show that the tendency of LCPs to diffuse parallel to the nematic orientation is responsible for the breakage of the network structure. [S1063-651X(99)14303-4].

    DOI: 10.1103/PhysRevE.59.3275

  • Free energy of semiflexible polymers and structure of interfaces 査読

    J Fukuda

    EUROPEAN PHYSICAL JOURNAL B   7 ( 4 )   573 - 583   1999年2月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The free energy of semiflexible polymers is calculated as a functional of the compositional scalar order parameter phi and the orientational order parameter of second-rank tensor S-ij on the basis of a microscopic model of wormlike chains with variable segment lengths. Mie use a density functional theory and a gradient expansion to evaluate the entropic part of the free energy, which is given in a power series of Q(ij) = S-ij/phi. The interaction term of the free energy is derived with a random phase approximation. For the rigid rod limit, the nematic-isotropic transition point is given by N omega phi = 4.05141, N and omega being the degree of polymerization and the anisotropic interaction parameter, respectively, and the degree of ordering at the transition point is 0.33448. We also find that the contour length of polymer chains becomes larger in a nematic phase than in an isotropic phase. Interface profiles are obtained numerically for some typical cases. In the neighborhood of isotropic-isotropic interfaces, polymer chains tend to align parallel to the interface on the polymer-rich side and perpendicular on the poor side. When an isotropic region and a nematic region coexist, orientational order parallel to the interface is preferred in the nematic region.

    DOI: 10.1007/s100510050650

  • Phase separation kinetics of nematic polymers: Coupling between compositional order and orientational order 査読

    J Fukuda

    PHYSICAL REVIEW E   58 ( 6 )   R6939 - R6942   1998年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We numerically investigate phase separation kinetics of liquid crystalline polymers in a nematic state using time-dependent Ginzburg-Landau equations for the compositional and the orientational order parameters phi and S-ij. The kinetics is significantly influenced by (i) the presence of the off-diagonal kinetic coefficient Lambda(phi S), (ii) the coupling between del phi and S-ij in the free energy, and (iii) the dependence of the kinetic coefficients on the orientational order. [S1063-651X(98)51312-8].

    DOI: 10.1103/PhysRevE.58.R6939

  • Effect of hydrodynamic flow on kinetics of nematic-isotropic transition in liquid crystals 査読

    J Fukuda

    EUROPEAN PHYSICAL JOURNAL B   1 ( 2 )   173 - 177   1998年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate kinetics of nematic-isotropic transition by solving the hydrodynamic equations for the nematic 3 x 3 tensor order parameter Q(alpha beta) and the fluid velocity in two space dimension (x-y plane). Numerical results indicate that nematic directors tend to align parallel to the x-y plane when hydrodynamic flow is incorporated. Late stage growth exponents, phi(C), for the correlation length and phi(def) for the number of topological defects, are not significantly altered by hydrodynamic flow. However, in contrast to the case without flow, the relation phi(def) = -2 phi(C) holds well, which may indicate the validity of dynamical scaling for the case with hydrodynamic flow.

    DOI: 10.1007/s100510050168

  • Interface dynamics in a block copolymer melt and the effect of noise 査読

    S Komura, J Fukuda, GC Paquette

    PHYSICAL REVIEW E   53 ( 6 )   R5588 - R5591   1996年6月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The role of fluctuations in the disorder-lamellar transition in a block copolymer melt is investigated using a cell dynamical system simulation by measuring the propagation velocity of the interface between ordered and disordered regions. Our results strongly suggest that near the transition temperature, in the absence of noise, the velocity increases with quench depth as upsilon similar to root tau [tau = (T-c - T)/T-c is the reduced temperature measured from the transition temperature T-c], while in the presence of noise, the velocity increases as upsilon similar to tau. These results lead us to conclude that the addition of noise causes the disorder-lamellar transition to change from second order to first order. This conclusion is consistent with the prediction of Brazovskii [Sov. Phys. JETP 41, 85 (1975)].

  • Interface dynamics in a block copolymer melt and the effect of noise 査読

    Shigeyuki Komura, Junichi Fukuda, Glenn C. Paquette

    Physical Review E - Statistical, Nonlinear, and Soft Matter Physics   53 ( 6 )   1996年1月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The role of fluctuations in the disorder-lamellar transition in a block copolymer melt is investigated using a cell dynamical system simulation by measuring the propagation velocity of the interface between ordered and disordered regions. Our results strongly suggest that near the transition temperature, in the absence of noise, the velocity increases with quench depth as [Formula Presented] [[Formula Presented] is the reduced temperature measured from the transition temperature [Formula Presented]], while in the presence of noise, the velocity increases as [Formula Presented]. These results lead us to conclude that the addition of noise causes the disorder-lamellar transition to change from second order to first order. This conclusion is consistent with the prediction of Brazovskii Sov. Phys. JETP 41 85 1975.

    DOI: 10.1103/PhysRevE.53.R5588

  • Electric field effects and form birefringence in diblock copolymers 査読

    A Onuki, J Fukuda

    MACROMOLECULES   28 ( 26 )   8788 - 8795   1995年12月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We investigate effects of the electric field on diblock copolymers by assuming an induced dipolar interaction among the composition fluctuations. First, we show that, when an electric field is applied perpendicularly to lamellae, undulations start to grow if their in-plane wavenumbers are smaller than an electric wavenumber q(e) proportional to the field. Subsequently, the undulations grow into larger spatial structures, eventually leading to a final square-lattice pattern. Second, we calculate the Maxwell stress tensor due to the electric field to predict a finite shear modulus in a lamellar state oriented by the electric field. Third, we examine form birefringence in disordered and ordered phases. In particular, the lamellar and hexagonal phases are shown to become birefringent on spatial scales longer than the spacing of lamellae or cylinders, even if the constituent monomers are optically isotropic. This gives rise to enhancement of depolarized light scattering from lamellar microstructures, which has indeed been observed recently. Most predictions in this paper are applicable to many situations other than those in the electric field.

    DOI: 10.1021/ma00130a011

  • SCATTERING FUNCTION OF THE DISORDERED PHASE OF BLOCK-COPOLYMERS UNDER SHEAR-FLOW 査読

    S KOMURA, J FUKUDA

    PHYSICS LETTERS A   208 ( 1-2 )   108 - 112   1995年11月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    The scattering function of the disordered phase of a block copolymer (BCP) melt under a steady shear flow is investigated by the cell dynamical system (CDS) approach. Agreement with previous theoretical calculations indicates the applicability of the CDS approach to the disordered phase as well as the ordered phase.

    DOI: 10.1016/0375-9601(95)00728-L

  • DYNAMICS OF UNDULATION INSTABILITY IN LAMELLAR SYSTEMS

    J FUKUDA, A ONUKI

    JOURNAL DE PHYSIQUE II   5 ( 8 )   1107 - 1113   1995年8月

     詳細を見る

    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    We numerically investigate dynamics of undulation instability of lamellar systems induced by an external field. In particular, if the field is much larger than the critical value, initial undulations are much finer than those in the final state. The coarsening law here is obtained both numerically and theoretically. We also demonstrate that the patterns are square grids if the field is perpendicular to the lamellae, while they are one-dimensional if it is parallel.

▼全件表示

講演・口頭発表等

  • Numerical study of the structural and optical properties of cholesteric blue phase liquid crystal 招待 国際会議

    福田順一

    The 7th International Soft Matter Conference  2023年9月 

     詳細を見る

    開催年月日: 2023年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:大阪   国名:日本国  

    その他リンク: https://ismc2023.jp

  • Exotic defect structures of a chiral liquid crystal sandwiched by two parallel substrates and their optical properties 招待 国際会議

    Jun-ichi FUKUDA

    SIAM Conference on Mathematical Aspects of Materials Science 2021 (MS21)  2021年5月 

     詳細を見る

    開催年月日: 2021年5月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

    その他リンク: https://www.siam.org/conferences/cm/conference/ms21

  • Exotic ordered structures of a thin film of a chiral liquid crystal and their optical properties 招待 国際会議

    J. Fukuda

    International Conference on Liquid Crystals, Liquid Crystalline Polymers and Nanosystem  2019年12月 

     詳細を見る

    開催年月日: 2019年12月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:Mahatma Gandhi Univ.   国名:インド  

  • Simulation Study on the Self-organized Structures of a Liquid Crystal 招待 国際会議

    J. Fukuda

    National Taiwan Normal UniversityーKyushu University Joint Forum on Facilitating Interdisciplinary Research and Education  2019年5月 

     詳細を見る

    開催年月日: 2019年5月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:台湾師範大学   国名:台湾  

  • Theoretical study on optical properties of liquid crystalline Skyrmion lattice 国際会議

    J. Fukuda and @S. Zumer

    SPIE Photonics West "Emerging Liquid Crystal Technologies XIV"  2019年2月 

     詳細を見る

    開催年月日: 2019年2月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:San Francisco   国名:アメリカ合衆国  

  • Exotic mesoscale structures in a thin film of a chiral liquid crystal 招待 国際会議

    J. Fukuda

    Soft Matter Physics: from the perspective of the essential heterogeneity  2018年12月 

     詳細を見る

    開催年月日: 2018年12月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:福岡   国名:日本国  

  • Half-Skyrmions in a chiral liquid crystal film 国際会議

    J. Fukuda, @A. Nych, @U. Ognysta, @S.Zumer, @I. Musevic

    The 27th International Liquid Crystal Conference  2018年7月 

     詳細を見る

    開催年月日: 2018年7月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:京都   国名:日本国  

  • Numerical study of martensitic transformation of a cubic blue phase liquid crystal 招待 国際会議

    福田順一

    Soft Matter Seminar  2024年3月 

     詳細を見る

    開催年月日: 2024年3月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:University of Ljubljana   国名:スロベニア共和国  

  • Cholesteric blue phase liquid crystal: Numerical studies of structural and optical properties 招待 国際会議

    福田順一

    Joint workshop: Physics Departments of NTNU and KU  2023年11月 

     詳細を見る

    開催年月日: 2023年11月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:台湾師範大学   国名:台湾  

  • コレステリックブルー相の構造相転移の連続体理論によるシミュレーショ

    福田順一

    2023年日本液晶学会討論会  2023年9月 

     詳細を見る

    開催年月日: 2023年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:東京理科大学(神楽坂キャンパス)   国名:日本国  

  • Simulation of structural relaxation and phase transition of liquid crystalline blue phases 招待 国際会議

    福田順一

    The 9th International Discussion Meeting on Relaxations in Complex Systems  2023年8月 

     詳細を見る

    開催年月日: 2023年8月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:千葉   国名:日本国  

    その他リンク: https://9idmrcs.jp

  • 液晶の秩序構造とその光学的性質に関する数値的研究 招待

    福田順一

    物性研究所スパコン共同利用・CCMS合同研究会「計算の時代における物性科学」  2023年4月 

     詳細を見る

    開催年月日: 2023年4月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:東京大学物性研究所   国名:日本国  

  • Simulation of the structures and optical properties of a cholesteric blue phase cell of finite thickness under an electric field 招待 国際会議

    福田順一

    OLC2021 Satellite Workshop  2022年9月 

     詳細を見る

    開催年月日: 2022年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:沖縄   国名:日本国  

  • 電場下における有限厚さのコレステリックブルー相液晶セルのシミュレーション

    福田順一

    2022年日本液晶学会討論会  2022年9月 

     詳細を見る

    開催年月日: 2022年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

  • Twin boundaries in cholesteric blue phase: A simulation study 国際会議

    #A. Yamashita, J. Fukuda

    The 28th International Liquid Crystal Conference  2022年7月 

     詳細を見る

    開催年月日: 2022年7月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:ポルトガル共和国  

  • Exotic structures and dynamics of frustrated cholesteric blue phases 招待

    福田順一

    東京大学物性研究所 理論セミナー  2022年7月 

     詳細を見る

    開催年月日: 2022年7月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:東京大学物性研究所   国名:日本国  

  • コレステリックブルー相の構造と光学的性質に関する数値計算 招待

    福田順一

    研究会「非平衡ソフトマター・アモルファス物質の物性解明への力学的自己組織化からの挑戦」  2022年6月 

     詳細を見る

    開催年月日: 2022年6月 - 2023年6月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:東京大学駒場キャンパス   国名:日本国  

  • キラルなフォトニック結晶におけるトポロジカル相

    #米澤弦起,福田順一

    第127回日本物理学会九州支部例会  2021年12月 

     詳細を見る

    開催年月日: 2021年12月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

  • Lattice orientation of cholesteric blue phases imposed by planar surface anchoring 国際会議

    Jun-ichi Fukuda, @Slobodan Zumer

    Optics of Liquid Crystals 2021 (OLC2021)  2021年9月 

     詳細を見る

    開催年月日: 2021年9月 - 2021年10月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

  • コレステリックブルー相の円偏光選択反射の入射角依存性

    福田順一,@趙 成龍,@吉田浩之@,尾崎雅則

    2021 年日本液晶学会討論会  2022年9月 

     詳細を見る

    開催年月日: 2021年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

  • Simulation study of twin boundaries of cholesteric blue phases 国際会議

    #A. Yamashita and J. Fukuda

    The 18th International Conference on Ferroelectric Liquid Crystals  2021年9月 

     詳細を見る

    開催年月日: 2021年9月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:スロベニア共和国  

  • BPI液晶の双晶の連続体シミュレーション

    #山下晃弘,福田順一

    第 126 回日本物理学会九州支部例会  2020年12月 

     詳細を見る

    開催年月日: 2020年12月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

  • BPI液晶の双晶の連続体シミュレーション

    #山下晃弘,福田順一

    2020年日本液晶学会オンライン発表会  2020年10月 

     詳細を見る

    開催年月日: 2020年10月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:オンライン   国名:日本国  

  • コレステリックブルー相の秩序形成の理論

    福田順一

    日本物理学会第75回年次大会  2020年3月 

     詳細を見る

    開催年月日: 2020年3月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:名古屋大学(学会自体は中止されたが,発表は有効の扱い)   国名:日本国  

  • キラル液晶薄膜の秩序構造とその光学的性質

    福田順一

    第9回ソフトな物理・工学の未来を考える会  2019年10月 

     詳細を見る

    開催年月日: 2019年10月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:東京大学本郷キャンパス   国名:日本国  

  • Exotic structures and their optical properties of a thin cell of a chiral liquid crystal 招待 国際会議

    J. Fukuda

    Soft Matter Seminar  2019年9月 

     詳細を見る

    開催年月日: 2019年9月

    記述言語:英語   会議種別:公開講演,セミナー,チュートリアル,講習,講義等  

    開催地:Univ. of Ljubljana   国名:スロベニア共和国  

  • キラル液晶薄膜が形成する秩序構造のKossel diagramによる解析

    福田順一, @A. Nych, @U. Ognysta, @S. Zumer,@ I. Musevic

    日本物理学会2019年秋季大会  2019年9月 

     詳細を見る

    開催年月日: 2019年9月 - 2018年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:岐阜大学   国名:日本国  

  • キラル液晶薄膜の秩序構造が示すKossel diagram

    福田順一, @A. Nych, @U. Ognysta, @S. Zumer,@ I. Musevic

    2019年日本液晶討論会  2019年9月 

     詳細を見る

    開催年月日: 2019年9月 - 2018年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:筑波大学   国名:日本国  

  • キラル液晶薄膜の特異な秩序構造とその光学

    福田順一

    ERATO横山液晶微界面プロジェクト 発足20周年記念研究会  2019年6月 

     詳細を見る

    開催年月日: 2019年6月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:箱根   国名:日本国  

  • Exotic ordered structures in a thin film of a chiral liquid crystal 招待 国際会議

    J. Fukuda

    The mathematical design of new materials  2019年4月 

     詳細を見る

    開催年月日: 2019年4月

    記述言語:英語   会議種別:公開講演,セミナー,チュートリアル,講習,講義等  

    開催地:Cambridge   国名:グレートブリテン・北アイルランド連合王国(英国)  

  • キラル液晶薄膜におけるスカーミオン格子の生成とその直接観察

    福田順一, @A. Nych, @U. Ognysta, @S. Zumer,@ I. Musevic

    2018年日本液晶討論会  2018年9月 

     詳細を見る

    開催年月日: 2018年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:岐阜大学   国名:日本国  

  • キラル液晶が示す特異な自己組織的秩序構造 招待

    福田順一

    第126回福工大土曜談話会  2018年4月 

     詳細を見る

    開催年月日: 2018年4月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:福岡工大   国名:日本国  

  • 液晶スカーミオンの配向構造とその直接観察

    福田順一,@Andriy Nych, @Uliana Ognysta, @Slobodan Zumer, @Igor Musevic

    日本物理学会第73回年次大会  2018年3月 

     詳細を見る

    開催年月日: 2018年3月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:東京理科大学野田キャンパス   国名:日本国  

  • Numerical calculation of Kossel diagrams of cholesteric blue phases 招待 国際会議

    福田順一,奥村泰志,菊池裕嗣

    SPIE Photonics West "Emerging Liquid Crystal Technologies XIII"  2018年1月 

     詳細を見る

    開催年月日: 2018年1月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:San Francisco   国名:アメリカ合衆国  

  • Liquid crystalline Skyrmions and their direct optical observation 招待 国際会議

    福田順一

    2017 International Workshop of A3 Foresight Program on Soft Matter  2017年12月 

     詳細を見る

    開催年月日: 2017年12月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:Chungnam National University   国名:大韓民国  

  • Skyrmions in a chiral liquid crystal film and their optical observation 国際会議

    福田順一

    The 7th Toyota Riken International Workshop on Chirality in Soft Matter  2017年11月 

     詳細を見る

    開催年月日: 2017年11月

    記述言語:英語   会議種別:口頭発表(一般)  

    開催地:名古屋   国名:日本国  

  • 液晶中に生じるスカーミオンとその直接観察 招待

    福田順一

    量子と古典の物理と幾何  2017年11月 

     詳細を見る

    開催年月日: 2017年11月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:九大箱崎キャンパス   国名:日本国  

  • キラル液晶セルの特異な秩序構造とその光学顕微鏡像

    福田順一,@Andriy Nych, @Uliana Ognysta, @Slobodan Zumer, @Igor Musevic

    第7回ソフトマター研究会  2017年10月 

     詳細を見る

    開催年月日: 2017年10月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:京都大学北部キャンパス   国名:日本国  

  • 液晶スカーミオンの光学顕微鏡像の数値計算

    福田順一

    第7回計算統計物理学研究会  2017年9月 

     詳細を見る

    開催年月日: 2017年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:東北大学片平キャンパス   国名:日本国  

  • コレステリックブルー相のKossel diagramの数値計算

    福田順一,奥村泰志,菊池裕嗣

    2017年日本液晶学会討論会  2017年9月 

     詳細を見る

    開催年月日: 2017年9月

    記述言語:日本語   会議種別:口頭発表(一般)  

    開催地:弘前大学   国名:日本国  

  • Localization of low-molecular-weight molecules at the defect of a liquid crystal 国際会議

    @大園拓哉,@加藤薫,福田順一

    The 10th Liquid Matter Conference (Liquids2017)  2017年7月 

     詳細を見る

    開催年月日: 2017年7月 - 2018年7月

    記述言語:英語   会議種別:口頭発表(一般)  

    国名:日本国  

▼全件表示

MISC

  • 書評「入門 ソフトマター物理学(松山明彦著,森北出版)」 査読

    福田順一

    液晶   2023年7月

     詳細を見る

    記述言語:日本語   掲載種別:書評論文,書評,文献紹介等  

  • 液晶物理・物性研究フォーラム講演会 『最新の光学イメージング手法とその液晶への応用』報告 査読

    福田順一

    液晶   2020年4月

     詳細を見る

    記述言語:日本語  

  • キラル液晶薄膜中のスカーミオンとその光学的性質

    福田順一,@Andriy Nych, @Uliana Ognysta, @Slobodan Zumer, @Igor Musevic

    液晶   2020年1月

     詳細を見る

    記述言語:日本語   掲載種別:記事・総説・解説・論説等(学術雑誌)  

  • 九州大学大学院理学研究院 物理学部門 物性理論研究室 査読

    福田順一

    液晶   2019年4月

     詳細を見る

    記述言語:日本語  

所属学協会

  • 分子シミュレーション研究会

  • 日本液晶学会

  • 日本物理学会

  • 日本物理学会

      詳細を見る

  • 日本液晶学会

      詳細を見る

  • 分子シミュレーション研究会

      詳細を見る

▼全件表示

委員歴

  • 日本液晶学会   代議員   国内

    2024年9月 - 現在   

      詳細を見る

    団体区分:学協会

  • 日本物理学会   代議員   国内

    2023年4月 - 2025年3月   

  • 日本物理学会   代議員   国内

    2021年4月 - 2023年3月   

  • 日本物理学会   九州支部長   国内

    2019年4月 - 2020年3月   

  • 日本物理学会   領域12代表   国内

    2015年4月 - 2016年3月   

  • 日本液晶学会   理事   国内

    2014年9月 - 2016年9月   

▼全件表示

学術貢献活動

  • Organizing Committee 国際学術貢献

    The 10th Japanese-Italian Joint Workshop on Liquid Crystals  ( 宮崎 ) 2024年9月

     詳細を見る

    種別:大会・シンポジウム等 

  • Local organizing committee member 国際学術貢献

    The 7th International Soft Matter Conference  ( 大阪 ) 2023年9月

     詳細を見る

    種別:大会・シンポジウム等 

  • Symposium Leader 国際学術貢献

    The 9th International Discussion Meeting on Relaxations in Complex Systems (9IDMRCS)  ( 幕張メッセ ) 2023年8月

     詳細を見る

    種別:大会・シンポジウム等 

  • The 9th International Discussion Meeting on Relaxations in Complex Systems (9IDMRCS) 国際学術貢献

    ( 幕張メッセ Japan ) 2023年8月

     詳細を見る

    種別:大会・シンポジウム等 

    researchmap

  • 学術論文等の審査

    役割:査読

    2023年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:14

  • 実行委員長

    第10回ソフトマター研究会  ( 九州大学西新プラザ ) 2022年11月

     詳細を見る

    種別:大会・シンポジウム等 

    参加者数:130

  • 第10回ソフトマター研究会

    ( 九州大学西新プラザ Japan ) 2022年11月

     詳細を見る

    種別:大会・シンポジウム等 

    researchmap

  • Frontiers in Soft Matter 国際学術貢献

    2022年2月 - 現在

     詳細を見る

    種別:学会・研究会等 

  • Frontiers in Soft Matter 国際学術貢献

    役割:審査・評価

    2022年2月

     詳細を見る

    種別:査読等 

    researchmap

  • 学術論文等の審査

    役割:査読

    2022年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:11

  • Program Committee 国際学術貢献

    Optics of Liquid Crystals 2021  ( 沖縄 ) 2021年9月

     詳細を見る

    種別:大会・シンポジウム等 

  • 学術論文等の審査

    役割:査読

    2021年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:11

  • Organizing Committee member 国際学術貢献

    Grand Views of Soft and Liquid Matter Physics  ( Tokyo Japan ) 2020年3月

     詳細を見る

    種別:大会・シンポジウム等 

  • Program Committee 国際学術貢献

    SPIE OPTO "Emerging Liquid Crystal Technologies"  ( San Francisco UnitedStatesofAmerica ) 2020年2月

     詳細を見る

    種別:大会・シンポジウム等 

  • 学術論文等の審査

    役割:査読

    2020年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:10

  • Crystals 国際学術貢献

    2019年7月 - 2022年4月

     詳細を見る

    種別:学会・研究会等 

  • Crystals 国際学術貢献

    役割:審査・評価

    2019年7月

     詳細を見る

    種別:査読等 

    researchmap

  • Program Committee 国際学術貢献

    SPIE OPTO "Emerging Liquid Crystal Technologies"  ( San Francisco UnitedStatesofAmerica ) 2019年2月

     詳細を見る

    種別:大会・シンポジウム等 

  • 学術論文等の審査

    役割:査読

    2019年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:9

  • Organizer 国際学術貢献

    Soft Matter Physics: from the perspective of the essential heterogeneity  ( Fukuoka Japan ) 2018年12月

     詳細を見る

    種別:大会・シンポジウム等 

  • Program Committee 国際学術貢献

    The 27th International Liquid Crystal Conference  ( 京都 ) 2018年7月

     詳細を見る

    種別:大会・シンポジウム等 

  • 日本学術振興会 研究者養成課 特別研究員等審査会 専門委員

    役割:審査・評価

    日本学術振興会  2018年7月 - 2020年6月

     詳細を見る

    種別:審査・学術的助言 

  • Program Committee 国際学術貢献

    SPIE OPTO "Emerging Liquid Crystal Technologies"  ( San Francisco UnitedStatesofAmerica ) 2018年1月

     詳細を見る

    種別:大会・シンポジウム等 

  • 学術論文等の審査

    役割:査読

    2018年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:10

  • Liquid Crystal Reviews 国際学術貢献

    2017年11月 - 現在

     詳細を見る

    種別:学会・研究会等 

  • Liquid Crystal Reviews 国際学術貢献

    役割:審査・評価

    2017年11月

     詳細を見る

    種別:査読等 

    researchmap

  • 学術論文等の審査

    役割:査読

    2017年

     詳細を見る

    種別:査読等 

    外国語雑誌 査読論文数:7

  • Scientific Reports 国際学術貢献

    2016年9月 - 現在

     詳細を見る

    種別:学会・研究会等 

  • Scientific Reports 国際学術貢献

    役割:審査・評価

    2016年9月

     詳細を見る

    種別:査読等 

    researchmap

▼全件表示

共同研究・競争的資金等の研究課題

  • 液晶が示す秩序構造とその機能,安定性に関する理論的研究

    2024年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • 液晶が示す秩序構造とその機能,安定性に関する理論的研究

    2023年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • Go-Tech事業

    2022年10月 - 2025年3月

      詳細を見る

    担当区分:研究分担者 

  • スマートグラスなどに内蔵する光方向を自在に制御する「液晶回折素子」測定システム開発

    2022年4月 - 2025年3月

    共同研究

      詳細を見る

    担当区分:研究分担者  資金種別:その他産学連携による資金

  • スマートグラスなどに内蔵する光方向を自在に制御する「液晶回折素子」測定システム開発

    2022年 - 2024年

    産業技術研究助成事業 (経済産業省)

      詳細を見る

    担当区分:研究分担者  資金種別:受託研究

  • 液晶が示す秩序構造とその機能,安定性に関する理論的研究

    2022年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • キラル液晶の秩序構造に基づくトポロジカルフォトニクスの理論的研究

    研究課題/領域番号:21H01049  2021年 - 2024年

    日本学術振興会  科学研究費助成事業  基盤研究(B)

      詳細を見る

    担当区分:研究代表者  資金種別:科研費

  • 液晶が示す秩序構造とその機能,安定性に関する理論的研究

    2021年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • 液晶が示す秩序構造とその機能,安定性に関する理論的研究

    2020年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • 液晶が示す秩序構造とその機能,安定性に関する理論的研究

    2019年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • コレステリックブルー相の構造とその安定性に関する理論的研究

    2018年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

  • 超先端材料超高速開発基盤技術プロジェクト

    2017年9月 - 2019年3月

      詳細を見る

    担当区分:研究分担者 

  • 液晶エラストマーのマルチスケール計算手法の開発

    2017年4月 - 2019年3月

    受託研究

      詳細を見る

    担当区分:研究分担者  資金種別:その他産学連携による資金

  • ソフトマターの秩序構造の光学的直接観察をサポートする理論的枠組みの構築

    研究課題/領域番号:17H02947  2017年 - 2020年

    日本学術振興会  科学研究費助成事業  基盤研究(B)

      詳細を見る

    担当区分:研究代表者  資金種別:科研費

  • コレステリックブルー相の構造とその安定性に関する理論的研究

    2017年

    物質・デバイス領域共同研究拠点 基盤共同研究

      詳細を見る

    担当区分:研究代表者  資金種別:受託研究

▼全件表示

教育活動概要

  • 2023年度は大学院向けの「非平衡物理学」,学部向けの「熱力学A,B」,基幹教育の「電磁気学基礎」「熱力学基礎」の講義を担当するとともに,修士2年の学生3名に対して修士号取得に向けた指導を行った.2022年度は大学院向けの「非平衡物理学」,及び学部向けの「統計力学I」の講義,3年次編入生向けの統計力学の補習を担当し,修士2年の学生1名に対して修士号取得に向けた指導を行った.2021年度は大学院向けの「非平衡物理学」,及び学部向けの「統計力学I」の講義を行うとともに,「物理学ゼミナール」での輪講,および3年次編入生向けの統計力学の補習も担当した.修士2年の学生3名に対して修士号取得に向けた指導を行った.またリカレント教育(高校教員の夏季研修会)においてソフトマターに関する講演を行なった.2020年度は大学院向けの「非平衡物理学」,及び学部向けの「統計力学I」の講義を行うとともに,「物理学ゼミナール」での輪講,および3年次編入生向けの統計力学の補習も担当した.修士2年の学生2名に対して修士号取得に向けた指導を行った.また高校生向けの「体験入学」においてソフトマターに関する講演を行った.2019年度は大学院向けの「非平衡物理学」,及び学部向けの「統計力学I」の講義を行うとともに,学部1年生向けの「物理学入門II」において,エントロピーに関する3回の講義を行った.また修士2年の学生1名に対して修士号取得に向けた指導を行った.2018年度は大学院向けの「非平衡物理学」,及び学部向けの「統計力学I」の講義を行うとともに,学部3年生向けの「最先端物理学」においてソフトマターに関する1回の講義を担当した.また3年次編入生向けの統計力学の補習も担当した.
     2017年度は「基幹物理学IA」,「統計力学I」といった物理学の基礎的な科目について講義を行うとともに,学部4年生にソフトマターに関する理論物理学の指導を卒業研究として行った.また確率過程の理論的研究を行っている博士課程の学生に主に論文執筆に関する指導を行い,博士の学位を取得させた.その他には,学部3年生向けの「最先端物理学」においてソフトマターに関する1回の講義を担当,高校生向けの体験入学でも,ソフトマターに関する講演を行うとともに,「物理学ゼミナール」での輪講も担当した.

担当授業科目

  • 熱力学基礎

    2023年12月 - 2024年2月   冬学期

  • 電磁気学基礎

    2023年10月 - 2023年12月   秋学期

  • 熱力学B

    2023年6月 - 2023年8月   夏学期

  • 非平衡物理学

    2023年4月 - 2023年9月   前期

  • 熱力学(R2以前入学者用)

    2023年4月 - 2023年9月   前期

  • 熱力学A

    2023年4月 - 2023年6月   春学期

  • 統計力学Ⅰ・同演習

    2022年10月 - 2023年3月   後期

  • 非平衡物理学

    2022年4月 - 2022年9月   前期

  • 物理学特別講義23

    2021年10月 - 2022年3月   後期

  • 統計力学Ⅰ・同演習

    2021年10月 - 2022年3月   後期

  • 非平衡物理学

    2021年4月 - 2021年9月   前期

  • 統計力学Ⅰ・同演習

    2020年10月 - 2021年3月   後期

  • 物理学ゼミナール

    2020年10月 - 2021年3月   後期

  • 非平衡物理学

    2020年4月 - 2020年9月   前期

  • 物理学特別講義4

    2019年10月 - 2020年3月   後期

  • 統計力学Ⅰ・同演習

    2019年10月 - 2020年3月   後期

  • 物理学入門II

    2019年10月 - 2020年3月   後期

  • 非平衡物理学

    2019年4月 - 2019年9月   前期

  • 物理学特別講義19

    2018年10月 - 2019年3月   後期

  • 統計力学Ⅰ・同演習

    2018年10月 - 2019年3月   後期

  • 非平衡物理学

    2018年4月 - 2018年9月   前期

  • 最先端物理学

    2018年4月 - 2018年9月   前期

  • 統計力学Ⅰ・同演習

    2017年10月 - 2018年3月   後期

  • 物理学ゼミナール

    2017年10月 - 2018年3月   後期

  • 基幹物理学ⅠA

    2017年4月 - 2017年9月   前期

  • 最先端物理学

    2017年4月 - 2017年9月   前期

▼全件表示

FD参加状況

  • 2024年3月   役割:参加   名称:大学教職員職能開発FD 「⽣成AIを大学の教育・学習・業務にどのように組み込むか?-第一弾 生成AIを使った授業デザイン支援のアイデア-」

    主催組織:全学

  • 2024年2月   役割:参加   名称:【物理学科FD】大学院の魅力創造に向けて

    主催組織:学科

  • 2023年3月   役割:参加   名称:【物理学科FD】物理数学の教育と効果的な演習に向けて

    主催組織:学科

  • 2022年3月   役割:参加   名称:メンタルヘルス講演会

    主催組織:全学

  • 2022年3月   役割:参加   名称:ティーチング・フェロー制度の概要と講義での活用

    主催組織:部局

  • 2022年3月   役割:参加   名称:TA制度の未来を考える〜九州大学の実践例を参考に〜

    主催組織:全学

  • 2021年3月   役割:講演   名称:【物理学FD】ハイブリッド講義の実践例と講義活性化

    主催組織:部局

  • 2021年3月   役割:参加   名称:FD講演会「九州大学オンライン授業のグッドプラクティス 〜 リアルタイム型授業編〜」

    主催組織:部局

  • 2020年12月   役割:参加   名称:【オンライン配信】新型コロナウィルス感染拡大状況での学生のメンタルヘルス

    主催組織:部局

  • 2019年12月   役割:参加   名称:AED,エピペンに関するFD

    主催組織:部局

  • 2019年7月   役割:参加   名称:3ポリシーに関する全学FD ~日本学術会議分野別参照基準に基づく理学部物理学科の3ポリシー~

    主催組織:全学

  • 2018年12月   役割:参加   名称:活気ある授業に向けたグループワーク・アクティブラーニング

    主催組織:学科

  • 2018年11月   役割:参加   名称:メンタルヘルス

    主催組織:全学

  • 2018年9月   役割:参加   名称:M2Bシステム

    主催組織:部局

  • 2018年8月   役割:参加   名称:大学入学試験についての高校教員と大学教員の意見交換会

    主催組織:部局

  • 2018年6月   役割:参加   名称:新入試QUBE説明会

    主催組織:全学

  • 2017年12月   役割:参加   名称:理学研究院・物理学部門ファカルティディベロプメント(FD) 講演会

    主催組織:部局

▼全件表示

他大学・他機関等の客員・兼任・非常勤講師等

  • 2021年  北里大学理学部  区分:集中講義  国内外の区分:国内 

    学期、曜日時限または期間:2021年11月19日

  • 2020年  東京都立大学理学系研究科物理学専攻  区分:集中講義  国内外の区分:国内 

    学期、曜日時限または期間:2020年12月2日から4日

その他教育活動及び特記事項

  • 2024年  クラス担任  学部

  • 2023年  クラス担任  学部

  • 2022年  クラス担任  学部

  • 2022年  学友会・同好会等の指導  2020年度入学生研修旅行(2022年9月実施)

     詳細を見る

    学年担任として引率

  • 2021年  クラス担任  学部

  • 2021年  その他特記事項  「液晶物理の基礎」 新化学技術推進協会 (JACI) ライフサイエンス技術部会 材料分科会 勉強会 オンライン講演

     詳細を見る

    「液晶物理の基礎」
    新化学技術推進協会 (JACI) ライフサイエンス技術部会 材料分科会 勉強会 オンライン講演

  • 2020年  クラス担任  学部

  • 2020年  その他特記事項  「液晶のLandau-de Gennes理論」電気学会四国支部主催講演会(オンライン講演)

     詳細を見る

    「液晶のLandau-de Gennes理論」電気学会四国支部主催講演会(オンライン講演)

▼全件表示

社会貢献・国際連携活動概要

  • 九州大学出版会 理事

社会貢献活動

  • 九州大学理学部先端自然科学講演会/福岡県高等学校理科部会 夏季研修会における講演「柔らかいものの物理」

    九州大学理学部/福岡県高等学校理科部会  オンライン  2021年8月

     詳細を見る

    対象:社会人・一般, 学術団体, 企業, 市民団体, 行政機関

    種別:講演会

  • 九州大学理学部先端自然科学講演会/福岡県高等学校理科部会 夏季研修会における講演「柔らかいものの物理」

    九州大学理学部/福岡県高等学校理科部会  オンライン  2021年8月

     詳細を見る

    種別:出前授業

    researchmap

  • 体験入学(高校生,高専生,一般向け)における講演「柔らかいものの物理」

    九州大学大学院理学研究院 物理学部門  オンライン  2021年3月

     詳細を見る

    対象:社会人・一般, 学術団体, 企業, 市民団体, 行政機関

    種別:講演会

  • 体験入学(高校生,高専生,一般向け)における講演(物理学科の紹介)

    九州大学大学院理学研究院 物理学部門  九大伊都キャンパス  2019年3月

     詳細を見る

    対象:社会人・一般, 学術団体, 企業, 市民団体, 行政機関

    種別:講演会

  • 体験入学(高校生,高専生,一般向け)における講演(物理学科の紹介)

    九州大学大学院理学研究院 物理学部門  九大伊都キャンパス  2019年3月

     詳細を見る

    種別:出前授業

    researchmap

  • 体験入学(高校生,高専生,一般向け)における講演「柔らかいものの物理」

    九州大学大学院理学研究院 物理学部門  九大伊都キャンパス  2018年3月

     詳細を見る

    対象:社会人・一般, 学術団体, 企業, 市民団体, 行政機関

    種別:講演会

▼全件表示

海外渡航歴

  • 2024年3月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2020年1月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2019年9月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2019年3月 - 2019年4月

    滞在国名1:グレートブリテン・北アイルランド連合王国(英国)   滞在機関名1:Isaac Newton Institute

  • 2016年9月 - 2016年10月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2013年12月 - 2014年2月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2012年10月 - 2013年3月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2010年12月 - 2011年3月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

  • 2009年1月 - 2009年7月

    滞在国名1:スロベニア共和国   滞在機関名1:リュブリャナ大学

▼全件表示

学内運営に関わる各種委員・役職等

  • 2019年5月 - 2021年4月   全学 入学試験実施委員会委員

  • 2018年4月 - 2019年3月   部門 物理学部門長/物理学専攻長/物理学科長