Localization phenomena in interacting Rydberg lattice gases with position disorder

TL;DR

This study investigates how intrinsic positional disorder in Rydberg atom systems leads to localization phenomena akin to Anderson localization, affecting excitation transfer and providing insights into many-body localization mechanisms.

Contribution

The paper demonstrates experimentally and theoretically that positional disorder in Rydberg gases causes localization effects similar to Anderson localization, linking microscopic disorder to many-body localization.

Findings

Suppression of excitation transfer observed in experiments.

Disorder modeled as an Anderson-like system on a lattice.

Localization linked to the absence of excitation propagation.

Abstract

Disordered systems provide paradigmatic instances of ergodicity breaking and localization phenomena. Here we explore the dynamics of excitations in a system of Rydberg atoms held in optical tweezers. The finite temperature produces an intrinsic uncertainty in the atomic positions, which translates into quenched correlated disorder in the interatomic interaction strengths. In a simple approach, the dynamics in the many-body Hilbert space can be understood in terms of a one-dimensional Anderson-like model with disorder on every other site, featuring both localized and delocalized states. We conduct an experiment on an eight-atom chain and observe a clear suppression of excitation transfer. Our experiment accesses a regime which is described by a two-dimensional Anderson model on a "trimmed" square lattice. Our results thus provide a concrete example in which the absence of excitation propagation in a many-body system is directly related to Anderson-like localization in the Hilbert space, which is believed to be the mechanism underlying many-body localization.