Experimental realization of a 3D long-range random hopping model

TL;DR

This paper experimentally investigates a 3D Rydberg system with random dipole-dipole couplings, revealing localization-delocalization transition signatures and enabling detailed study of transport and localization phenomena in strongly correlated quantum systems.

Contribution

It demonstrates the realization of a 3D long-range random hopping model using Rydberg atoms and observes spectroscopic signatures of localization-delocalization transition.

Findings

Good agreement with an effective spin model

Spectroscopic signatures of localization-delocalization transition

Potential to study interplay of randomness and strong correlations

Abstract

Randomness and disorder have strong impact on transport processes in quantum systems and give rise to phenomena such as Anderson localization [1-3], many-body localization [4] or glassy dynamics [5]. Their characteristics thereby depend on the strength and type of disorder. An important class are hopping models, where particles or excitations move through a system which has randomized couplings. This includes, e.g., spin glasses [5], coupled optical waveguides [6], or NV center arrays [7]. They are also key to understand excitation transport in molecular and biological systems, such as light harvesting complexes [8]. In many of those systems, the microscopic coupling mechanism is provided by the dipole-dipole interaction. Rydberg systems [9] are therefore a natural candidate to study random hopping models. Here, we experimentally study a three-dimensional many-body Rydberg system with random dipole-dipole couplings. We measure the spectrum of the many-body system and find good agreement with an effective spin model. We also find spectroscopic signatures of a localization-delocalization transition. Our results pave the way to study transport processes and localization phenomena in random hopping models in detail. The inclusion of strong correlations is experimentally straightforward and will allow to study the interplay between random hopping and localization in strongly interacting systems.