Decoherence of edge states in two-dimensional Floquet systems with temporal noise

Two-dimensional periodically driven systems exhibit interesting topological features which cannot be achieved in static systems.

Anomalous Floquet topological insulators (AFTI) are one such example.

AFTIs are known to withstand more spatial disorder than any other Floquet topological phases in a temporal noise-free case.

In this work, we show that a two-dimensional AFTI is more robust to temporal noise than a Floquet Chern Insulator (FCI).

We obtain our results by computing the survival probability and the time-averaged velocity expectation of an edge state.

We observe that the survival probability of an edge state is exponentially decaying in both AFTI and FCI phases.

In contrast, the velocity decays as a power law in an AFTI and decays exponentially in an FCI.

However, the exponent of the power law decay can be changed by altering the spatial disorder in an AFTI away from resonant driving, a feature not seen in an FCI.