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 $z=1.72(2)$, $\beta /\nu =0.41(2)$, and $\gamma /\nu =2.90(5)$ . We compare our results to other quantum phase transitions in disordered systems, and we discuss experiments.

10 pages, 3 pdf figures included, builds on arXiv:1607.01860, submitted to the Proceedings of CCP 2016

References in corpus (17)

• Rare region effects at classical, quantum, and non-equilibrium phase transitions
• The critical exponents of the superfluid transition in He4
• Bose glass and Mott glass of quasiparticles in a doped quantum magnet
• Quantum Griffiths effects in itinerant Heisenberg magnets
• Phase transition of one dimensional bosons with strong disorder
• Effects of dissipation on a quantum critical point with disorder
• Infinite-randomness quantum critical points induced by dissipation
• Theory of smeared quantum phase transitions
• Particle-hole symmetry and the dirty boson problem
• Percolation quantum phase transitions in diluted magnets
• A Mott Glass to Superfluid Transition for Random Bosons in Two Dimensions
• Quantum phase transitions of the diluted O(3) rotor model
• Quantum critical behavior of the superfluid-Mott glass transition
• Emerging criticality in the disordered three-color Ashkin-Teller model
• Asymptotically Exact Scenario of Strong-Disorder Criticality in One-Dimensional Superfluids
• Disordered bosons in one dimension: from weak to strong randomness criticality
• Percolation transition and dissipation in quantum Ising magnets

Cited by in corpus (1)

• Inhomogeneous mean-field approach to collective excitations in disordered interacting bosons