Nonlinear optical effects in noncentrosymmetric magnets
The responses of materials to high intensity light, i.e., nonlinear optical responses, constitute a vast field of physics and engineering. One of nonlinear optical responses that is attracting a recent attention is a bulk photovoltaic effect called shift current which arises from Berry phase of a Bloch wave function and has a close relationship to the modern theory of electric polarization . In this talk, I will present a bulk photovoltaic effect supported by magnets nonlinear through the shift current mechanism . In noncentrosymmetric magnets, magnons generally accompany electric polarization due to their multiferroic nature and couple to an external electric field. Constant excitation of such magnons causes an increase of electric polarization and results in dc photocurrent. I will demonstrate that a shift current appears in the cycloidal phase in J1-J2 spin chains with broken inversion symmetry. T. Morimoto, and N. Nagaosa, Sci. Adv. 2, e1501524 (2016).
 T. Morimoto, S. Kitamura, S. Okumura, Phys. Rev. B 104, 075139 (2021).
Chair: Yong Baek Kim
This event is jointly organized by the Korea Institute for Advanced Study and the University of Tokyo. “Correlated Electrons Virtual International Seminars (CEVIS)” https://sites.google.com/view/cevis2020/home