Tohoku University. Research Profiles


Transport Control of Semiconductor Quantum Structures and Highly Sensitive NMR



Highly-sensitive NMR technique has been developed by manipulation polarization of nuclear spins via control of transport characteristics in GaAs and InSb quantum structures. This highly-sensitive NMR can be applied to two-dimensional and nanostructures. Furthermore, ideal gate controllability has been demonstrated in InSb quantum structures with Al2 O3 dielectrics. More importantly, the concept of generalized coherence time was introduced, where noise characteristics felt by nuclear spins can be measured including their frequency dependence. This concept will bring about a change in all nuclear-spin related measurements.

Targeted Application(s)/Industry

Next generation InSb devices based on good gate controllability. Various nuclear-spin based measurements and NMR utilizing the concept of generalized coherence time. Highly-sensitive NMR is now important for fundamental physics studies. In the future, it will contribute to quantum information processing.


Graduate School of Science

HIRAYAMA Yoshiro , Professor
Doctor of Engineering


Related Information

Tatsuro Yuge, Susumu Sasaki, and Yoshiro Hirayama, “Measurement of noise spectrum using a multiple-pulse sequence”, Phys. Rev. Lett. 107, 170504 (2011)
M. M. Uddin, H. W. Liu, K. F. Yang, K. Nagase, T. D. Mishima, M. B. Santos, and Y. Hirayama, “Characterization of InSb quantum wells with atomic layer deposited gate dielectrics”, Appl. Phys. Lett. 101, 233503 (2012).
Yoshiro Hirayama, “Contact hyperfine interactions and resistively-detected NMR”, chapter 38, Quantum Hall Effect by Z. F. Ezawa (World Scientific) (to be published).