# Floquet theory of laser-induced control of topology in solids

Takashi Oka, MPI PKS Dresden

13.05.2016 at 09:00

The effect of strong laser on the topology of many body systems is becoming a hot topic [1,2,3]. A theoretical proposal was made in two dimensional Dirac systems where an application of circularly polarized light was shown to turn the system into a quantum Hall state [1,2]. One can see this as a dynamical realization of the Haldane model of a quantum Hall state without Landau levels [4]. This effect can be understood with the help of the Floquet theory of driven quantum systems, where the circularly polarized light plays the role similar to the “next nearest hopping with a nontrivial phase factor” in the Haldane model.

We extend this idea to other systems such as multiferroics and two dimensional electron gas.

[1] T. Oka and H. Aoki: Phys. Rev. B 79, 081406 (2009).

[2] T. Kitagawa, T. Oka, A. Brataas, L. Fu, E. Demler: Phys. Rev. B 84, 235108 (2011).

[3] N. H. Lindner, G. Refael, V. Galitski: Nat. Phys. 7 490 (2011).

[4] F. D. M. Haldane: Phys. Rev. Lett. 61 2015 (1988).

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