The main research subject of our laboratory is theoretical study of quantum transport in nano-scale devices based on various methods. This research subject, which is also called ‘mesoscopic physics’, has been studied for long time by focusing on quantum mechanical nature of electrons. Recently, mesoscopic systems are studied from novel viewpoints such as nonequilibrium many-body phenomena, shot noise, high-speed drive phenomena, spintronics, and so on. In order to explain these phenomena, we are constructing theories by utilizing nonequilibrium statistical mechanics, fundamental theory of quantum mechanics, and many-body physics. Examples of our recent activities are nonequilibruim transport properties of the Kondo quantum dots, electron and heat transport under time-dependent external fields, and many-body effect in thermal transport of phonons.

Upper panel: A schematic figure of the Hong-Ou-Mandel-type two-electron collision experiment. Two electrons injected from two quantum dots propagate along edge states, and collides at a central quantum point contact. Lower panel: The probability P, that two electrons scatter into the same edge states, is plotted as a function of a wavepacket delay time Δt.

The photon-assisted zero-bias noise (the solid line) and the equilibrium thermal noise (the dashed line) evaluated at the corresponding T_{eff} (the right inset) are displayed as a function of the strength of the external filed. The left inset: a schematic picture of the present model.

Temperature-Driven and Electrochemical-Potential-Driven Adiabatic Pumping via a Quantum Dot: M. Hasegawa and T. Kato, J. Phys. Soc. Jpn.86 (2017) 024710.

Quantum Fluctuations along Symmetry Crossover in a Kondo-Correlated Quantum Dot: M. Ferrier, T. Arakawa, T. Hata, R. Fujiwara, R. Delagrange, R. Deblock, Y. Teratani, R. Sakano, A. Oguri and K. Kobayashi, Phys. Rev. Lett.118 (2017) 196803.

3.

「General formalism for adiabatic charge pumping induced by reservoir parameter modulation in quantum dot systems」 M. Hasegawa, 東京大学理学系研究科 (2017).