# Probing disorder-driven topological phase transitions via topological edge modes with ultracold atoms in Floquet-engineered honeycomb lattices

## TL;DR

This paper demonstrates how disorder can induce phase transitions between different Floquet topological phases in ultracold atom systems, using edge mode properties in driven honeycomb lattices, advancing the study of topology under disorder.

## Contribution

It introduces a method to probe disorder-driven topological phase transitions with ultracold atoms, overcoming previous limitations related to lattice translational invariance.

## Key findings

- Disorder drives phase transitions between Floquet topological phases.
- Disorder enhances the robustness of the anomalous Floquet topological regime.
- Confirmation that disorder favors anomalous Floquet topological phases.

## Abstract

One of the most fascinating properties of topological phases of matter is their robustness to disorder and imperfections. Although several experimental techniques have been developed to probe the geometric properties of engineered topological Bloch bands with cold atoms, they almost exclusively rely on the translational invariance of the underlying lattice. This prevents direct studies of topology in the presence of disorder, further hindering an extension to disordered interacting topological phases. Here, we identify disorder-driven phase transitions between two distinct Floquet topological phases using the characteristic properties of topological edge modes with ultracold atoms in periodically-driven two-dimensional (2D) optical lattices. Our results constitute an important step towards studying the rich interplay between topology and disorder with cold atoms. Moreover, our measurements confirm that disorder indeed favors the anomalous Floquet topological regime over conventional Hall systems, indicating an enhanced robustness and paving the way towards observing exotic out-of-equilibrium phases such as the anomalous Floquet Anderson insulator.