paper

Distinct Floquet topological classifications from color-decorated frequency lattices with space-time symmetries

arXiv:2305.18532 · doi:10.1103/PhysRevB.108.L180302

Abstract

We consider nontrivial topological phases in Floquet systems using unitary loops and stroboscopic evolutions under a static Floquet Hamiltonian in the presence of dynamical space-time symmetries . While the latter has been subject of out-of-equilibrium classifications that extend the ten-fold way and systems with additional crystalline symmetries to periodically driven systems, we explore the anomalous topological zero modes that arise in from the coexistence of a dynamical space-time symmetry and antisymmetry of , and classify them using a frequency-domain formulation. Moreover, we provide an interpretation of the resulting Floquet topological phases using a frequency lattice with a decoration represented by color degrees of freedom on the lattice vertices. These colors correspond to the coefficient of the group extension of along the frequency lattice, given by . The distinct topological classifications that arise at different energy gaps in its quasi-energy spectrum are described by the torsion product of the cohomology group classifying the group extension.

arXiv comment4 pages + supplementary material

References in corpus (51)

Cited by in corpus (3)