Disordered bosons in one dimension: from weak- to strong-randomness criticality

Phys Rev Lett. 2012 Dec 28;109(26):265303. doi: 10.1103/PhysRevLett.109.265303. Epub 2012 Dec 27.

Abstract

We investigate the superfluid-insulator quantum phase transition of one-dimensional bosons with off-diagonal disorder by means of large-scale Monte Carlo simulations. For weak disorder, we find the transition to be in the same universality class as the superfluid-Mott insulator transition of the clean system. The nature of the transition changes for stronger disorder. Beyond a critical disorder strength, we find nonuniversal, disorder-dependent critical behavior. We compare our results to recent perturbative and strong-disorder renormalization group predictions. We also discuss experimental implications as well as extensions of our results to other systems.