Optically engineering the topological properties of a spin Hall insulator

Balázs Dóra (1, 2) , Jérôme Cayssol (3, 4, 5) , Ferenc Simon (1) , Roderich Moessner (5)

1 Department of Physics [Budapest]
2 BME-MTA Exotic Quantum Phases Research Group
3 LOMA - Laboratoire Ondes et Matière d'Aquitaine
4 Department of Physics [Berkeley]
5 MPI-PKS - Max Planck Institute for the Physics of Complex Systems

Time-periodic perturbations can be used to engineer topological properties of matter by altering the Floquet band structure. This is demonstrated for a spin Hall insulator in the presence of monochromatic circularly polarized light. The inherent spin structure of the edge state is influenced by the Zeeman coupling and not by the orbital effect. The photocurrent (and the magnetization along the edge) develops a finite, helicity dependent expectation value and turns from dissipationless to dissipative with increasing radiation frequency, signalling a change in the topological properties. The connection with Thouless' charge pumping and non-equilibrium Zitterbewegung is discussed, together with possible experiments.

Mots clés: Spin polarized transport in semiconductors; Phases: geometric - dynamic or topological; Spin transport effects; Graphene

Domaines: Matière Condensée [cond-mat]

Balázs Dóra, Jérôme Cayssol, Ferenc Simon, Roderich Moessner. Optically engineering the topological properties of a spin Hall insulator. Physical Review Letters, 2012, 108 (5), pp.056602. ⟨10.1103/PhysRevLett.108.056602⟩. ⟨hal-00670801⟩