Theory of light-induced Floquet topological states

CFEL Theory Seminar

  • Datum: 20.01.2016
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Michael Sentef
  • Max Planck Institute for the Structure and Dynamics of Matter, Hamburg
  • Ort: CFEL (Bldg. 99)
  • Raum: Seminar Room IV, O1.111
  • Gastgeber: Angel Rubio
Theory of light-induced Floquet topological states

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 [1]. 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.

[1] M. A. Sentef et al., Nature Communications 6, 7047 (2015)
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