Superfluid--Insulator Transition in Commensurate One-Dimensional Bosonic System with Off-Diagonal Disorder

TL;DR

This paper investigates the superfluid-insulator transition in a one-dimensional disordered bosonic system, finding that the transition shares the same universality class as the pure system's superfluid-Mott insulator transition, due to disorder self-averaging.

Contribution

It demonstrates that the universality class remains unchanged in the presence of off-diagonal disorder for large filling factors, supported by Monte Carlo simulations and theoretical analysis.

Findings

Transition shares universality class with pure system

Disorder self-averaging explains universality

Conditions for strong-randomness universality class are formulated

Abstract

We study the nature of the superfluid--insulator quantum phase transition in a one-dimensional system of lattice bosons with off-diagonal disorder in the limit of large integer filling factor. Monte Carlo simulations of two strongly disordered models show that the universality class of the transition in question is the same as that of the superfluid--Mott-insulator transition in a pure system. This result can be explained by disorder self-averaging in the superfluid phase and applicability of the standard quantum hydrodynamic action. We also formulate the necessary conditions which should be satisfied by the stong-randomness universality class, if one exists.