Aharonov-Bohm Caging and Inverse Anderson transition in Ultracold Atoms

TL;DR

This paper reports the experimental realization of Aharonov-Bohm caging and inverse Anderson transition in ultracold atoms within a synthetic lattice, highlighting the interplay of flat band localization, disorder, and gauge fields in quantum transport.

Contribution

It demonstrates the first experimental observation of AB caging and inverse Anderson transition in a synthetic ultracold atom system with engineered gauge fields.

Findings

Observation of geometric localization due to flat band

Demonstration of inverse Anderson transition with binary disorder

Control of localization and transport via gauge fields

Abstract

Aharonov-Bohm (AB) caging, a special flat-band localization mechanism, has spurred great interest in different areas of physics. AB caging can be harnessed to explore the rich and exotic physics of quantum transport in flatband systems, where geometric frustration, disorder and correlations act in a synergetic and distinct way than in ordinary dispersive band systems. In contrast to the ordinary Anderson localization, where disorder induces localization and prevents transport, in flat band systems disorder can induce mobility, a phenomenon dubbed inverse Anderson transition. Here, we report on the experimental realization of the AB cage using a synthehtic lattice in the momentum space of ultracold atoms with tailored gauge fields, demonstrate the geometric localization due to the flat band and the inverse Anderson transition when correlated binary disorder is added to the system. Our experimental platform in a many-body environment provides a fashiinating quantum simulator where the interplay between engineered gauge fields, localization, and topological properties of flat band systems can be finely explored.