Kyushu University Academic Staff Educational and Research Activities Database
Researcher information (To researchers) Need Help? How to update
Takeaki Yajima Last modified date:2023.09.28

Graduate School
Undergraduate School

E-Mail *Since the e-mail address is not displayed in Internet Explorer, please use another web browser:Google Chrome, safari.
 Reseacher Profiling Tool Kyushu University Pure
Academic Degree
Doctor (Science)
Country of degree conferring institution (Overseas)
Field of Specialization
Oxide thin films, electronic device and circuit, neuromorphic system
Total Priod of education and research career in the foreign country
Outline Activities
Research and education on the fields of oxide thin films, electronic devices and circuits, and neuromorphic systems.
Research Interests
  • Constructive electronics
    keyword : oxide thin film, semiconductor, hydrogen, metal-insulator transition, low-power technology, edge learning, energy harvesting, CMOS circuit
Academic Activities
1. Zero-dimensionality of a scaled-down VO2 metal-insulator transition via high-resolution electrostatic gating.
2. Ultra-low-power switching circuits based on a binary pattern generator with spiking neurons.
3. Low Power IoT Circuit Technology Using Spiking Neuron Circuits.
4. T. Yajima, T. Tanaka, Y. Samata, K. Uchida, A. Toriumi, High-speed low-energy heat signal processing via digital-compatible binary switch with metal-insulator transitions., International Electron Devices Meeting (IEDM), 10.1109/IEDM19573.2019.8993502, 903-906, 2019.12.
5. T. Yajima, G. Oike, S. Yamaguchi, S. Miyoshi, T. Nishimura, A. Toriumi, Hydrogenation of the wide-gap oxide semiconductor as a room-temperature and 3D-compatible electron doping technique., AIP Advances, 10.1063/1.5055302, 8, 115133, 2018.09.
6. T. Yajima, T. Nishimura, and A, Toriumi, Analog Spike Processing with High Scalability and Low Energy Consumption Using Thermal Degree of Freedom in Phase Transition Materials., VLSI (Technology), 10.1109/VLSIT.2018.8510649, 18, 27-28, 2018.07.
7. Takeaki Yajima, Tomonori Nishimura, Akira Toriumi, Identifying the Collective Length in VO2 Metal-Insulator Transitions, SMALL, 10.1002/smll.201603113, 13, 12, 2017.03.
8. T. Yajima, T. Nishimura, A. Toriumi, Functional Passive Material VO2 for Analogue Signal Processing with High-Speed, Low Power, and Robust Performance, Technical Digest - International Electron Devices Meeting, IEDM, 10.1109/IEDM.2016.7838540, 2016.12.
9. Takeaki Yajima, Go Oike, Tomonori Nishimura, Akira Toriumi, Independent control of phases and defects in TiO2 thin films for functional transistor channels, PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE, 10.1002/pssa.201600006, 213, 8, 2196-2202, 2016.08.
10. Takeaki Yajima, Tomonori Nishimura, Akira Toriumi, Positive-bias gate-controlled metal-insulator transition in ultrathin VO2 channels with TiO2 gate dielectrics, NATURE COMMUNICATIONS, 10.1038/ncomms10104, 6, 2015.12.
11. Yajima, Takeaki, Hikita, Yasuyuki, Minohara, Makoto, Bell, Christopher, Mundy, Julia A., Kourkoutis, Lena F., Muller, David A., Kumigashira, Hiroshi, Oshima, Masaharu, Hwang, Harold Y, Controlling band alignments by artificial interface dipoles at perovskite heterointerfaces, Nature Communications, 10.1038/ncomms7759, 2015.06.
12. Takeaki Yajima, Yuma Ninomiya, Tomonori Nishimura, Akira Toriumi, Drastic change in electronic domain structures via strong elastic coupling in VO2 films, PHYSICAL REVIEW B, 10.1103/PhysRevB.91.205102, 91, 20, 2015.05.
13. Yajima, Takeaki, Minohara, Makoto, Bell, Christopher, Kumigashira, Hiroshi, Oshima, Masaharu, Hwang, Harold Y., Hikita, Yasuyuki, Enhanced Electrical Transparency by Ultrathin LaAlO3 Insertion at Oxide Metal/Semiconductor Heterointerfaces, Nano Letters, 10.1021/nl504169m, 2015.02.
14. Takeaki Yajima, Yasuyuki Hikita, Harold Y. Hwang, A heteroepitaxial perovskite metal-base transistor, NATURE MATERIALS, 10.1038/NMAT2946, 10, 3, 198-201, 2011.03.
1. Trends in Power Supply Circuit Technology for Widespread Use of Energy Harvesting.
2. Design of neuromorphic information devices using protons.
Membership in Academic Society
  • Material Research Society
  • JSAP Silicon Technology Devision
  • IEEE
  • Young Scientist Award by Minister of Education, Culture, Sports, Science and Technology
  • Bachelor Thesis Award
  • Presentation Award
  • Poster Award
  • Graduate Student Award
  • 26th Innovative Frontier Technology Award
  • Young Scientist Award
  • Yasuda Award
  • R & D Encouragement Award
  • Poster Award
  • The 8th Silicon Technology Division Award
  • 40th Japan Society of Applied Physics Paper Award
  • PREST Exchange Meeting, Poster Award
  • Young Researcher Award
  • Excellency in Research in oxide electronics
Educational Activities
Teaching Fundamentals of Electromagnetism and Application of Quantum Mechanics I for bachelor course. Teaching Neuromorphic Hardware and Group Research Proposal for EEE in graduate school.