The quasi-particle gap in a disordered boson Hubbard model in two dimensions
arXiv:cond-mat/0511579 · doi:10.1103/PhysRevB.72.212515
Abstract
We investigate the behavior of the quasi-particle energy gap near quantum phase transitions in a two-dimensional disordered boson Hubbard model at a commensurate filling. Via Monte Carlo simulations of ensembles with fixed numbers of particles, we observe the behavior of the gap as a function of the tuning parameter for various strength of diagonal disorder. For weak disorder, we find that gapped Mott insulating phase is sustained up to the transition point and disappears only in a superfluid, strongly supporting a direct Mott-insulator-to-superfluid transition. Bose glass behavior, insulating with vanishing gap, appears only when the strength of disorder is bigger than a critical value.
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Cited by in corpus (5)
- Cold Bosons in Optical Lattices
- Particle-hole symmetry and the dirty boson problem
- Quantum Phase Transitions of Hard-Core Bosons in Background Potentials
- Gutzwiller approach to the Bose-Hubbard model with random local impurities
- Quantum Monte Carlo study of a magnetic-field-driven 2D superconductor-insulator transition