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Chirality in Quantum Dynamics


Speaker:Prof. Naoto Nagaosa
Affiliation:RIKEN Center for Emergent Matter Science (CEMS) & Department of Applied Physics, University of Tokyo
Date:June 19, 2019 (Wednesday)
Time:2:30 p.m.
Venue:Room 522, 5/F, Chong Yuet Ming Physics Building, HKU

Abstract


When the system lacks both parity and mirror symmetries, it is called “chiral” and can be classified into right-handed and left-handed. Chirality is one of the most fundamental issues in many branches of sciences [1]. In biology, the chirality of DNA is the same for all the living creatures on earth. In chemistry, to synthesize the molecules of one chirality selectively is an important issue. In physics, the parity violation is a striking feature of weak interaction.
In this talk, I will focus on the chirality appearing in quantum dynamics, and discuss that the most fundamental principles in physics manifest themselves in the nonreciprocal responses of chiral systems, i.e., the symmetries, dissipation, quantum-classical crossover/transition, quantal Berry phase and topology, and many-body correlation effects. The concrete examples to discuss include magnetochiral anisotropy of semiconductors [2], Weyl semimetals [3], and superconductors [4], nonlinear spin current generation in Rashba-Dresselhaus systems, and shift currents under photo-excitations [5].
The collaborators of these works are T. Morimoto, K.W. Kim, R. Wakatsuki, K. Hamamoto, M. Ezawa, H. Ishizuka, S. Hoshino, S.Koshikawa, S.Shimizu, Y.Kaneko Y. Saito, T. Ideue, Y. Iwasa, and Y. Tokura.

References:
[1] M. Gardner, The Ambidextrous Universe. Left, Right and the Fall of Parity, Basic Books Inc. (1964).
[2] T. Ideue et al., Nature Physics 13, 578-583 (2017).
[3] T. Morimoto and N. Nagaosa, Phys. Rev. Lett. 117, 146603 (2016).
[4] R. Wakatsuki et al., Science Advances 3, e1602390 (2017).
[5] T. Morimoto and N. Nagaosa, Science Advances 2, e1501524 (2016).

Coffee and tea will be served 20 minutes prior to the seminar.

Anyone interested is welcome to attend.