Dynamics of pattern-loaded fermions in bichromatic optical lattices

TL;DR

This paper investigates the non-thermalizing dynamics of interacting fermions in bichromatic optical lattices, providing computational insights that align with experimental observations of many-body localization phenomena.

Contribution

It introduces a low-density cluster expansion method to model fermion dynamics in Aubry-Andre systems, extending analysis to two dimensions and matching experimental results.

Findings

Agreement with experimental imbalance measurements

Demonstration of many-body localization signatures

Extension of models to two-dimensional systems

Abstract

Motivated by experiments in Munich (M. Schreiber et. al. Science \textbf{349}, 842), we study the dynamics of interacting fermions initially prepared in charge density wave states in one-dimensional bichromatic optical lattices. The experiment sees a marked lack of thermalization, which has been taken as evidence for an interacting generalization of Anderson localization, dubbed "many-body localization". We model the experiments using an interacting Aubry-Andre model and develop a computationally efficient low-density cluster expansion to calculate the even-odd density imbalance as a function of interaction strength and potential strength. Our calculations agree with the experimental results and shed light on the phenomena. We also explore a two-dimensional generalization. The cluster expansion method we develop should have broad applicability to similar problems in non-equilibrium quantum physics.