Universal Superfluid Transition and Transport Properties of Two-Dimensional Dirty Bosons

Giuseppe Carleo (1) , Guilhem Boéris (1) , Markus Holzmann (2, 3) , Laurent Sanchez-Palencia (1)

1 Laboratoire Charles Fabry / Optique atomique
2 LPTMC - Laboratoire de Physique Théorique de la Matière Condensée
3 LPM2C - Laboratoire de physique et modélisation des milieux condensés

We study the phase diagram of two-dimensional, interacting bosons in the presence of a correlated disorder in continuous space, using large-scale finite temperature quantum Monte Carlo simulations. We show that the superfluid transition is strongly protected against disorder. It remains of the Berezinskii-Kosterlitz-Thouless type up to disorder strengths comparable to the chemical potential. Moreover, we study the transport properties in the strong disorder regime where a zero-temperature Bose-glass phase is expected. We show that the conductance exhibits a thermally activated behavior and strictly vanishes only at zero temperature. Our results do not show any evidence of a finite-temperature localization transition, and point towards the existence of Bose bad-metal phase as a precursor of the Bose-glass phase.

Domaines: Gaz Quantiques [cond-mat.quant-gas]

Giuseppe Carleo, Guilhem Boéris, Markus Holzmann, Laurent Sanchez-Palencia. Universal Superfluid Transition and Transport Properties of Two-Dimensional Dirty Bosons. 2013. ⟨hal-00822056v1⟩