Nonreciprocal transport in Landau-Zener problem*

Responses of quantum materials against external stimuli show a rich variety according to the symmetries of the underlying microscopic Hamiltonian. In particular, nonreciprocal response with a directional transport is an important class of phenomena, which can emerge in noncentrosymmetric materials. As typified in Onsager’s reciprocal relation, however, the presence of the time-reversal symmetry sometimes forbids the directionality.

In this talk, we report two types of new nonreciprocal transport peculiar to time-reversal symmetric insulating systems. One is the dissipative electric current with a nonreciprocal tunneling probability, which emerges due to the geometric correction to the Landau-Zener formula [1]. The other is the spin transport in the presence of the assymetic spin-orbit coupling, which arises due to the assymetric momentum distribution peculiar to the tunneling electrons in a dissipative environment [2].

[1] S. Kitamura, N. Nagaosa, and T. Morimoto, Commun. Phys. 3, 63 (2020).
[2] S. Kitamura, N. Nagaosa, and T. Morimoto, arXiv:2009.03596.