Higher-order topological insulators (HOTIs) have emerged as a new class of phases, whose robust in-gap "corner" modes arise from the bulk higher-order multipoles beyond the dipoles in conventional topological insulators. Here, we incorporate Floquet driving into HOTIs, and report for the first time a dynamical polarization theory with anomalous nonequilibrium multipoles. Further, a proposal to detect not only corner states but also their dynamical origin in cold atoms is demonstrated, with the latter one never achieved before. Experimental determination of anomalous Floquet corner modes is also proposed.
Physical Review Letters
- Pub Date:
- May 2020
- Condensed Matter - Strongly Correlated Electrons;
- Condensed Matter - Quantum Gases
- 4+2+18 pages, major update for a new anomalous dynamical polarization theory