Competition and interplay between topology and quasi-periodic disorder in Thouless pumping of ultracold atoms

TL;DR

This paper experimentally investigates how quasi-periodic disorder influences topological pumping in ultracold atoms, revealing disorder-induced topological phases and the competition between disorder and topology in a controllable optical lattice system.

Contribution

It demonstrates the first controlled observation of disorder-induced topological pumping in a Thouless pump with ultracold atoms, highlighting the interplay between disorder and topology.

Findings

Disorder can induce a non-trivial topological pump in a system that is trivial without disorder.

The system exhibits a transition from trivial to topological phases as disorder strength increases.

The platform allows for future studies of disorder effects and interactions in topological quantum phenomena.

Abstract

Robustness against perturbations lies at the heart of topological phenomena. If, however, a perturbation such as disorder becomes dominant, it may cause a topological phase transition between topologically non-trivial and trivial phases. Here we experimentally reveal the competition and interplay between topology and quasi-periodic disorder in a Thouless pump realized with ultracold atoms in an optical lattice, by creating a quasi-periodic potential from weak to strong regimes in a controllable manner. We demonstrate a disorder-induced pumping in which the presence of quasi-periodic disorder can induce a non-trivial pump for a specific pumping sequence, while no pump is observed in the clean limit. Our highly controllable system, which can also straightforwardly incorporate interatomic interaction, could be a unique platform for studying various disorder-related novel effects in a wide range of topological quantum phenomena.