Topological index for periodically driven time-reversal invariant 2D systems.

@article{Carpentier2015TopologicalIF,
  title={Topological index for periodically driven time-reversal invariant 2D systems.},
  author={David Carpentier and Pierre Delplace and Michel Fruchart and Krzysztof Gawȩdzki},
  journal={Physical review letters},
  year={2015},
  volume={114 10},
  pages={
          106806
        }
}
We define a new Z2-valued index to characterize the topological properties of periodically driven two dimensional crystals when the time-reversal symmetry is enforced. This index is associated with a spectral gap of the evolution operator over one period of time. When two such gaps are present, the Kane-Mele index of the eigenstates with eigenvalues between the gaps is recovered as the difference of the gap indices. This leads to an expression for the Kane-Mele invariant in terms of the Wess… CONTINUE READING