Critical Properties of the Superfluid - Bose Glass Transition in Two Dimensions

Abstract

We investigate the superfluid (SF) to Bose glass (BG) quantum phase transition using extensive quantum Monte Carlo simulations of two-dimensional hard-core bosons in a random box potential. $T=0$ critical properties are studied by thorough finite-size scaling of condensate and SF densities, both vanishing at the same critical disorder $W_c=4.80(5)$. Our results give the following estimates for the critical exponents: $z=1.85(15)$, $\nu =1.20(12)$, $\eta =-0.40(15)$. Furthermore, the probability distribution of the SF response $P(\ln {\rho }_{\mathrm{sf}})$ displays striking differences across the transition: while it narrows with increasing system sizes $L$ in the SF phase, it broadens in the BG regime, indicating an absence of self-averaging, and at the critical point $P(\ln {\rho }_{\mathrm{sf}}+z\ln L)$ is scale invariant. Finally, high-precision measurements of the local density rule out a percolation picture for the SF-BG transition.

4 pages, 5 figures + supplementary material

References in corpus (9)

• Localization of preformed Cooper-pairs in disordered superconductors
• Strongly interacting bosons in a disordered optical lattice
• The quasi-periodic Bose-Hubbard model and localization in one-dimensional cold atomic gases
• Strongly disordered TiN and NbTiN s-wave superconductors probed by microwave electrodynamics
• Phase transition of interacting disordered bosons in one dimension
• Particle-hole symmetry and the dirty boson problem
• Frequency dependent superfluid stiffness in the pseudogap regime in strongly disordered NbN thin films
• Quantum Phase Transitions of Hard-Core Bosons in Background Potentials
• Strong-disorder renormalization-group study of the one-dimensional tight-binding model

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• Quantum crystallography of Rydberg-dressed Bose gases on a square lattice