2015/06/25 by Frederik Nathan, Mark S. Rudner · 2 citations
Physics and Astronomy · #cond-mat.mes-hall
paper · pdf · doi:10.1088/1367-2630/17/12/125014
published as New J. Phys. 17, 125014 (2015) · 19 pages, 6 figures
arxiv created 2015/06/25 · arxiv updated 2019/01/24
Recent works have demonstrated that the Floquet-Bloch bands of periodically-driven systems feature a richer topological structure than their non-driven counterparts. The additional structure in the driven case arises from the periodicity of quasienergy, the energy-like quantity that defines the spectrum of a periodically-driven system. Here we develop a new paradigm for the topological classification of Floquet-Bloch bands, based on the time-dependent spectrum of the driven system's evolution operator throughout one driving period. Specifically, we show that this spectrum may host topologically-protected degeneracies at intermediate times, which control the topology of the Floquet bands of the full driving cycle. This approach provides a natural framework for incorporating the role of symmetries, enabling a unified and complete classification of Floquet-Bloch bands and yielding new insight into the topological features that distinguish driven and non-driven systems.