Geometric nonlinear optical effects
- March 16 at 17:00 - 18:15, 2021 (JST)
- Prof. Takahiro Morimoto (Associate Professor, Department of Applied Physics, The University of Tokyo)
- via Zoom
Time: 5pm ~ 6:15pm (JST); 9am ~ 10:15am (CET)
The responses of materials to high intensity light, i.e., nonlinear optical responses, constitute a vast field of physics and engineering. While geometry and topology has been playing a central role in recent studies of condensed matters, geometrical aspects of nonlinear optical effects have not been fully explored so far. In this talk, I will show a few examples of nonlinear optical effects that have geometrical origins. First, I present that the second-order nonlinear optical effects including the shift-current, a candidate mechanism for recently discovered solar cell action in perovskite materials, has a close relationship to the modern theory of polarization, and is described by the Berry connection of Bloch wave function . I will also discuss how electron correlations can enhance/modify shift current response in inversion broken materials. Next, I show that another second-order nonlinear effect, circular photogalvanic effect (CPGE), is governed by Berry curvature and shows quantization in Weyl semimetals . I will report a recent measurement on chiral multifold fermion RhSi that observed a plateau structure in CPGE which is consistent with the expected quantization .
*Detailed information about the seminar refer to the email.
- T. Morimoto, and N. Nagaosa, Sci. Adv. 2, e1501524 (2016).
- F. de Juan, A. G. Grushin, T. Morimoto, and J. E. Moore, Nat. Commun. 8, 15995 (2017).
- D. Rees, K. Manna, B. Lu, T. Morimoto, H. Borrmann, C. Felser, J. Moore, D. Torchinsky, J. Orenstein, Sci. Adv. 6, eaba0509 (2020).