Details
  • Title: Floquet engineering and geometric dynamical effects in quantum materials
  • Speaker: Professor Takashi Oka,The Institute for Solid State Physics, The University of Tokyo
  • Date: Wednesday, June 29, 2022, 14:00
  • ZOOM meeting: 852 9400 4317(online)
Report Summaries:

In this talk, I will discuss recent progress in controlling material properties with laser fields. Specifically, I will focus on the coherent dynamics of electrons and spins generated by pulsed laser fields, emphasizing geometric dynamical effects. An important concept is Floquet engineering, which controls quantum systems using periodic driving [1]. One can effectively realize Floquet topological insulators, chiral spin liquids, and even chiral superconductors by irradiating circularly polarized lasers. If time permits, I will explain other geometric effects, such as the twisted Landau-Zener tunneling discussed by M.V. Berry in the tunneling mechanism of electron-hole pair production [2].

[1] TO, Kitamura, Annu. Rev. Condens. Matter Phys. 10, 387 (2019)
[2] Takayoshi, Wu, TO, SciPost Phys. 11, 075 (2021).

About the Speaker:

Professor Oka obtained his PhD in physics from the University of Tokyo in 2005. After a sojourn in Germany, where he was a group leader in both the Max Planck Institute for the Physics of Complex Systems, and the Max Planck Institute for the Chemical Physics of Solids, he returned to his alma mater and is presently a professor at the Institute for Solid State Physics. Prof. Oka has done many influential works in the field of strongly correlated electrons and nonequilibrium dynamics, and was recognized by many awards. This year, he was a recipient of the Japan Academy Medal for his contribution to the “theory of dynamical control of quantum materials”.