Voltage noise in one-dimensional Floquet topological insulators.

We consider a periodically-driven SSH model coupled to two external leads at the edges. Using a Floquet-Green's functions approach, we determine the fluctuations in occupation numbers in the system as a function of position, chemical potential, frequency (power spectrum), and drive frequency, which can be related to voltage noise in the system. For a static SSH model in the topological regime, the noise power spectrum presents a zero-frequency peak when the chemical potential of both leads is set to zero. This peak originates from transitions between the two zero-energy modes localized at the edges, and is absent in the trivial regime. We will present results for the analogue of this in a driven SSH model. We also consider disorder in the form of a random static potential, and identify the robust features in the power spectrum. Finally, we discuss the relevance of our results for experiments.