Topological boundary invariants for Floquet systems and quantum walks
arXiv:1708.01173 · doi:10.1007/s11040-017-9253-1
Abstract
A Floquet systems is a periodically driven quantum system. It can be described by a Floquet operator. If this unitary operator has a gap in the spectrum, then one can define associated topological bulk invariants which can either only depend on the bands of the Floquet operator or also on the time as a variable. It is shown how a K-theoretic result combined with the bulk-boundary correspondence leads to edge invariants for the half-space Floquet operators. These results also apply to topological quantum walks.
Correction of several misprints, added references, to appear in Mathematical Physics, Analysis, Geometry