Disordered bosons in one dimension: from weak- to strong-randomness criticality.
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.
Department of Physics, Missouri University of Science and Technology, Rolla, Missouri 65409, USA.
Fawaz
F
Hrahsheh
Thomas
T
Vojta