Superfluid-Mott Glass Quantum Multicritical Point on a Percolating Lattice

Abstract

We employ large-scale Monte Carlo simulations to study a particle-hole symmetric site-diluted quantum rotor model in two dimensions. The ground state phase diagram of this system features two distinct quantum phase transitions between the superfluid and the insulating (Mott glass) phases. They are separated by a multicritical point. The generic transition for dilutions below the lattice percolation threshold is driven by quantum fluctuations while the transition across the percolation threshold is due to the geometric fluctuations of the lattice. We determine the location of the multicritical point between these two transitions and find its critical behavior. The multicritical exponents read z=1.72(2), ß/ν=0.41(2), and γ/ν=2.90(5) . We compare our results to other quantum phase transitions in disordered systems, and we discuss experiments.

Meeting Name

28th IUPAP Conference on Computational Physics (2016: Jul. 10-14, Pretoria, South Africa)

Department(s)

Physics

Research Center/Lab(s)

Center for High Performance Computing Research

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 The International Union of Pure and Applied Physics, All rights reserved.

Publication Date

01 Jul 2016

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