# Localization, topology and quantized transport in disordered Floquet systems

## TL;DR

This paper explores how periodic driving in disordered one-dimensional systems can induce a transition from localized to delocalized Floquet states, enabling nearly-quantized transport despite Anderson localization of eigenstates.

## Contribution

It reveals a disorder-induced transition in Floquet states linked to topological properties, showing how driving can delocalize states and produce quantized transport in disordered systems.

## Key findings

- Floquet states can delocalize in driven disordered systems
- A transition occurs at a nontrivial loop in parameter space
- Delocalized phase features a continuous Floquet spectrum

## Abstract

We investigate the transition induced by disorder in a periodically-driven one-dimensional model displaying quantized topological transport. We show that, while instantaneous eigenstates are necessarily Anderson localized, the periodic driving plays a fundamental role in delocalizing Floquet states over the whole system, henceforth allowing for a steady state nearly-quantized current. Remarkably, this is linked to a localization/delocalization transition in the Floquet states of a one dimensional driven Anderson insulator, which occurs for periodic driving corresponding to a nontrivial loop in the parameter space. As a consequence, the Floquet spectrum becomes continuous in the delocalized phase, in contrast with a pure-point instantaneous spectrum.