Disorder-induced topological phase transitions

Our recent study on disorder-induced Floquet topological phase transitions has been published!

The impact of weak disorder and its spatial correlation on the topology of a Floquet system is not well
understood so far. In this study, we investigate a model closely related to a two-dimensional Floquet system that has been realized in our K-hexagonal lattice experiment. In the absence of disorder, we determine the phase diagram and identify an exotic phase characterized by edge states with alternating chirality in adjacent gaps. When weak disorder is introduced, we examine the disorder-averaged Bott index and analyze why the anomalous Floquet topological insulator is favored by both uncorrelated and correlated disorder, with the latter having a stronger effect. For a system with a ring-shaped gap in the energy spectrum, the Born approximation fails to explain the topological phase transition, unlike for a system with a pointlike gap.

Original publication:
Floquet topological phase transitions induced by uncorrelated or correlated disorder
Jun-Hui Zheng, Arijit Dutta, Monika Aidelsburger, Walter Hofstetter
Phys. Rev. B 109, 184201 (2024)