A Superglass Phase of Interacting Bosons

TL;DR

This paper introduces a disordered Bose-Hubbard model and demonstrates through quantum Monte Carlo simulations that a stable superglass phase, where superfluidity and glassy behavior coexist, can exist without phase separation.

Contribution

It presents the first evidence of a stable superglass phase in a disordered interacting boson system using both numerical and mean-field methods.

Findings

Superglass phase coexists with superfluidity and glassiness.

Disordered interactions stabilize the superglass phase.

The superglass phase persists in the infinite-dimensional limit.

Abstract

We introduce a Bose-Hubbard Hamiltonian with random disordered interactions as a model to study the interplay of superfluidity and glassiness in a system of three-dimensional hard-core bosons at half-filling. Solving the model using large-scale quantum Monte Carlo simulations, we show that these disordered interactions promote a stable superglass phase, where superflow and glassy density localization coexist in equilibrium without exhibiting phase separation. The robustness of the superglass phase is underlined by its existence in a replica mean-field calculation on the infinite-dimensional Hamiltonian.