Theory of light-induced Floquet topological states
14:00 - 15:00
Max Planck Institute for the Structure and Dynamics of Matter, Hamburg
CFEL (Bldg. 99)
Seminar Room IV, O1.111
In this talk, I will discuss the theory of effective Floquet Hamiltonians and band structures in the context of periodically laser-driven solids. I will give a brief introduction to Floquet states and their connection to time-resolved photoemission spectroscopy measured during an optical laser pump in a pump-probe setup. I will also briefly introduce topological states of matter and related concepts of Berry phases, Berry curvatures, pseudospin and the topological classification of band structures.
As an example, I will discuss our recent work on ultrafast Floquet band formation and local pseudospin textures induced by laser modulation of Berry curvatures in a model calculation for graphene . Furthermore, I will outline possible future developments in theory as well as experiments, highlighting the intriguing possibility of tailoring band structures and their topology using specifically tailored laser pulses.
 M. A. Sentef et al., Nature Communications 6
, 7047 (2015)