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Yuichiro Kurokawa Last modified date:2020.11.18





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https://kyushu-u.pure.elsevier.com/en/persons/yuichiro-kurokawa
 Reseacher Profiling Tool Kyushu University Pure
http://mag.ed.kyushu-u.ac.jp/indexE.html
Academic Degree
Ph. D. in Engineering
Country of degree conferring institution (Overseas)
No
Field of Specialization
spintronics, nanotechnology
Total Priod of education and research career in the foreign country
00years10months
Research
Research Interests
  • Spin seebeck effect based on magnetic nanoparticles
    keyword : Spintronics, Thermoelectric conversion
    2019.04.
  • Investigation of magnetic domain wall memory
    Investigation of spin logic

    keyword : spintronics
    2017.04.
Academic Activities
Papers
1. Shilei Ding, Andrew Ross, Romain Lebrun, Sven Becker, Kyujoon Lee, Isabella Boventer, Souvik Das, Yuichiro Kurokawa, Shruti Gupta, Jinbo Yang, Gerhard Jakob, and Mathias Kläui, Interfacial Dzyaloshinskii-Moriya interaction and chiral magnetic textures in a ferrimagnetic insulator, PHYSICAL REVIEW B, https://doi.org/10.1103/PhysRevB.100.100406, 100, 100406(R), 100, 100406(R) (2019), 2019.09, The interfacial Dzyaloshinskii-Moriya interaction (DMI) in multilayers of heavy metal and ferromagnetic metals enables the stabilization of novel chiral spin structures such as skyrmions. Magnetic insulators, on the other hand, can exhibit enhanced dynamics and properties such as lower magnetic damping and therefore it is of interest to combine the properties enabled by interfacial DMI with insulating systems. Here, we demonstrate the presence of interfacial DMI in heterostructures that include insulating magnetic layers. We use perpendicularly magnetized insulating thulium iron garnet (TmIG) films capped by the heavy metal platinum, grown on gadolinium gallium garnet (GGG) substrates, and find a surprisingly strong interfacial DMI that, combined with spin-orbit torque, results in efficient switching. The interfacial origin is confirmed through thickness-dependence measurements of the DMI, revealing the characteristic 1/thickness dependence. We combine chiral spin structures and spin-orbit torques for efficient switching and identify skyrmions that allow us to establish the GGG/TmIG interface as the possible origin of the DMI..
2. Yuichiro Kurokawa, Masakazu Wakae, Satoshi Sumi, Hiroyuki Awano, Kohei Ohnishi, Hiromi Yuasa, Spin-orbit torque-driven current-induced domain wall motion in Gd-Fe magnetic wires, Japanese Journal of Applied Physics, 10.7567/1347-4065/aafa91, 58, 3, 2019.03, We fabricated Gd-Fe/Ta/sub. and W/Gd-Fe/Ta/sub. perpendicular magnetized magnetic wires and investigated current-induced domain wall motion (CIDWM) in them. The propagation field of the Gd-Fe wires is low (∼3 mT), and the wires were found to have a low threshold current density (∼3.1 ×1010 A m-2) of CIDWM. The directions of the CIDWM in Gd-Fe/Ta and W/Gd-Fe/Ta wires are opposite to each other, indicating that the CIDWM in both wires is driven by spin-orbit torque because the spin Hall torque generated by the Ta underlayer and W cap layer oppose each other..
3. Masakazu Wakae, Yuichiro Kurokawa, Hiromi Yuasa, Observation of spin-orbit torque-induced magnetization switching in Gd-Fe perpendicular magnetized wire with in-plane exchange bias field, Japanese Journal of Applied Physics, 10.7567/1347-4065/aaf877, 58, 2019.01, We fabricated a Ta/Gd-Fe/Ta and a Ta/Gd-Fe/Ir22Mn78/Co90Fe10/Ta multilayered magnetic wire and investigated spin-orbit torque current-induced magnetization switching in these wires. Magnetization switching in the Ta/Gd-Fe/Ir22Mn78/Co90Fe10/Ta multilayered magnetic wire can be observed by an electric current even if the external in-plane magnetic field is not applied at all. Moreover, we successfully observed the periodical magnetization switching in the Ta/Gd-Fe/Ir22Mn78/Co90Fe10/Ta multilayered magnetic wire in zero magnetic field. This indicates that the present wire is a promising material to realize magnetic random access memory with low power consumption..
4. Yuichiro Kurokawa, Hiroyuki Awano, Multilayered current-induced domain wall motion in Pt/Tb-Co/Ta/Tb-Co/Pt magnetic wire, AIP ADVANCES, 10.1063/1.5017814, 8, 2, 2018.02, We fabricated a Pt (3 nm)/Tb0.28Co0.72 (4 nm)/Ta (4 nm)/Tb0.26Co0.74 (4 nm)/Pt
(3 nm) multilayered magnetic wire and investigated current-induced domain wall
motion within it.We found that the Hall resistance of the Pt/Tb-Co/Ta/Tb-Co/Pt wire
has four stable levels under a magnetic field of zero. Moreover, we observed that the
domain walls in both the upper and lower ferromagnetic layers are controlled by a
single current source. This indicates that Pt/Tb-Co/Ta/Tb-Co/Pt wire can be used in
multi-level magnetic wire memory..
5. Yuichiro Kurokawa, Akihiro Shibata, Hiroyuki Awano, Enhancement of spin orbit torques in a Tb-Co alloy magnetic wire by controlling its Tb composition, AIP ADVANCES, 10.1063/1.4974280, 7, 5, 2017.05.
6. @Yuichiro Kurokawa, Ryogo Yoshimura, Satoshi Sumi, Hiroyuki Awano, Thermal reduction of the threshold current density for current-induced domain wall motion in Tb-Co magnetic alloy wire, AIP ADVANCES, 10.1063/1.4979727, 7, 3, 2017.03.
7. Yuichiro Kurokawa, Masaya Kawamoto, Hiroyuki Awano, Current-induced domain wall motion attributed to spin Hall effect and Dzyaloshinsky-Moriya interaction in Pt/GdFeCo (100 nm) magnetic wire, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.7567/JJAP.55.07MC02, 55, 7, 2016.07.
8. Yuichiro Kurokawa, Takehiko Hihara, Ikuo Ichinose, Critical field of two-dimensional superconducting Sn1-x/Si x bimetallic composite cluster assembled films with energetic cluster impact deposition, Journal of Applied Physics, 10.1063/1.4798262, 113, 17, 2013.05.
Presentations
1. Yuichiro Kurokawa, Masakazu Wakae, Masahiro Itoh, Satoshi Sumi, Hiroyuki Awano, Kohei Ohnishi, Hiromi Yuasa, Investigation of Y-shaped magnetic wire logic device by current-induced domain wall motion, 第66回応用物理学会春季学術講演会, 2019.03.
2. Masakazu Wakae, Masahiro Itoh, Yuichiro Kurokawa, Kohei Ohnishi, Hiromi Yuasa, Observation of spin-orbit torque magnetization switching in Gd-Fe perpendicular magnetized wire with IrMn cap layer, 第66回応用物理学会春季学術講演会, 2019.03.
3. Yuichiro Kurokawa, Current-induced domain wall motion in rare-earth transition-metal alloy magnetic wire for future memory, CARN-OSAKA Annual Workshop 2018, 2018.12.
4. Yuichiro Kurokawa, Satoshi Sumi, Hiroyuki Awano, Hiromi Yuasa, Multilayered current-induced domain wall motion for high density magnetic memory, 9th Joint European Magnetic Symposia, 2018.09.
5. Masakazu Wakae, Yuichiro Kurokawa, Hiromi Yuasa, Observation of Spin-Orbit Torque Magnetization Switching in Gd-Fe Perpendicular Magnetized Wire without External Magnetic Field, 2018 International Conference on Solid State Devices and Materials, 2018.09.
6. Masakazu Wakae, Yuichiro Kurokawa, Hiromi Yuasa, Observation of spin-orbit torque magnetization switching in Gd-Fe perpendicular magnetized wire without external magnetic field, 第65回 応用物理学会 春季学術講演会, 2018.03.
7. Yuichiro Kurokawa, Masakazu Wakae, Ryogo Yoshimura, Hiroyasu Kondo, Satoshi Sumi, Hiroyuki Awano, Hiromi Yuasa, Investigation of current-induced domain wall motion in Gd-Fe wire with low domain wall propagation filed, 第65回 応用物理学会 春季学術講演会, 2018.03.
8. Yuichiro Kurokawa, Current-induced domain wall motion in rare-earth transition-metal alloy magnetic wire, SKKU and Kyushu university Joint Workshop, 2018.01.
Membership in Academic Society
  • The Magnetics Society of Japan
  • The Japan Society of Applied Physics
  • The Physical Society of Japan