Publication Date

2004

Journal or Book Title

Physics Review Letters

Abstract

Two sorts of bosons in an optical lattice at commensurate filling factors can form five stable superfluid and insulating ground states with rich and nontrivial phase diagram. The structure of the ground state diagram is established by mapping a d-dimensional quantum system onto a (d+1)-dimensional classical loop-current model and Monte Carlo (MC) simulations of the latter. Surprisingly, the quantum phase diagram features, besides second-order lines, first-order transitions and two multicritical points. We explain why first-order transitions are generic for models with pairing interactions using microscopic and mean-field (MF) arguments. In some cases, the MC results strongly deviate from the MF predictions.

Comments

This is the pre-published version harvested from ArXiv. The published version is located at http://prl.aps.org/abstract/PRL/v92/i5/e050402

Volume

92

Issue

5

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