Physics and device applications of semiconductor quantum nanostructures

3.1 Data Processing Device/Material (Scaled CMOS, Novel Switch, 3D Integration, etc.)
3.4 Data Generation Device/Material (Novel Sensor Device, etc.)
3.7 Advanced Device/Material Evaluation Measurement Techniques (SEM, AFM, OCD, TEM, etc.)

Kazuhiko Hirakawa

Institute of Industrial Science

Professor　Director, Professor　Institute for Nano Quantum Information Electronics

In the nanometer-sized semiconductor structures (quantum nanostructures), new physics based on quantum mechanics appear. We conduct the research with the goal of elucidating new physics that appear in such "quantum semiconductors" and applying them to novel device applications. In particular, we investigate the electronic properties and carrier dynamics in quantum nanostructures using ultra-high frequency electromagnetic waves called terahertz (THz) radiation, and developing novel devices for generation and detection of THz electromagnetic waves as well as thermionic cooling devices.

Single electron transistor using a single self-assembled InAs quantum dot
M. Jung, T. Machida, K. Hirakawa, S. Komiyama, T. Nakaoka, S. Ishida, and Y. Arakawa, Applied Physics Letters, vol. 87, No. 20, pp. 203109-1~3 (2005).

Sensitive and fast terahertz bolometer using a doubly-clamped MEMS beam resonator
Y. Zhang, Y. Watanabe, S. Hosono, Nagai, and K. Hirakawa, Applied Physics Letters, vol. 108, pp. 163503-1~4 (2016).

Research collaborators

The University of Tokyo
Tohoku University
Tokyo University of Agriculture and technology
National Institute for Communications Technology
Ecole Normale Superieure (France)
LIMMS-CNRS (France)
University of Twente (the Netherlands)

Related publications

N. Sekine and K. Hirakawa: "Dispersive terahertz gain of non-classical oscillator: Bloch oscillation in semiconductor superlattices”, Physical Review Letters, vol. 94, No. 5, 057408 (2005).
Y. Zhang, K. Shibata, N. Nagai, C. Ndebeka-Bandou, G. Bastard, and K. Hirakawa: “Terahertz intersublevel transitions in single self-assembled InAs quantum dots with variable electron numbers”, Nano Letters, vol. 15, pp. 1166~1170 (2015).
Y. Zhang, Y. Watanabe, S. Hosono, Nagai, and K. Hirakawa: “Room temperature, very sensitive thermometer using a doubly clamped microelectromechanical beam resonator for bolometer applications”, Applied Physics Letters, vol. 108, pp. 163503-1~4 (2016).
A. Yangui, M. Bescond, T. Yan, N. Nagai and K. Hirakawa: “Evaporative electron cooling in asymmetric double barrier semiconductor heterostructures”, Nature Communications, (2019)10: 4504.