Many body localization proximity effects in platforms of coupled spins and bosons

TL;DR

This paper investigates how many-body localization can be induced in coupled spin and boson systems through proximity effects, using theoretical models and potential quantum optics implementations.

Contribution

It introduces a model of coupled spins and bosons to study proximity-induced many-body localization and derives effective Hamiltonians to analyze phase stability.

Findings

Proximity effects can induce many-body localization in coupled systems.

Effective Hamiltonians reveal conditions for localized phases.

Feasibility of experimental realization in quantum optics platforms.

Abstract

We discuss the onset of many body localisation in a one-dimensional system composed of a XXZ quantum spin chain and a Bose-Hubbard model linearly coupled together. We consider two complementary setups depending whether spatial disorder is initially imprinted on spins or on bosons; in both cases, we explore the conditions for the disordered portion of the system to localise by proximity of the other clean half. Assuming that the dynamics of one of the two parts develops on shorter time scales than the other, we can adiabatically eliminate the fast degrees of freedom, and derive an effective hamiltonian for the system's remainder using projection operator techniques. Performing a locator expansion on the strength of the many-body interaction term or on the hopping amplitude of the effective hamiltonian thus derived, we present results on the stability of the many body localised phases induced by proximity effect. We also briefly comment on the feasibility of the proposed model through modern quantum optics architectures, with the long-term perspective to realize experimentally, in composite open systems, Anderson or many-body localisation proximity effects.