Publication Date

2009

Journal or Book Title

Physics Review Letters

Abstract

We prove the absence of a direct quantum phase transition between a superfluid and a Mott insulator in a bosonic system with generic, bounded disorder. We also prove the compressibility of the system on the superfluid–insulator critical line and in its neighborhood. These conclusions follow from a general theorem of inclusions, which states that for any transition in a disordered system, one can always find rare regions of the competing phase on either side of the transition line. Quantum Monte Carlo simulations for the disordered Bose-Hubbard model show an even stronger result, important for the nature of the Mott insulator to Bose glass phase transition: the critical disorder bound Δc corresponding to the onset of disorder-induced superfluidity, satisfies the relation Δc>Eg/2, with Eg/2 the half-width of the Mott gap in the pure system.

Comments

This is the pre-published version harvested from ArXiv. The published version is located at http://prl.aps.org/abstract/PRL/v103/i14/e140402

Volume

103

Issue

14

Included in

Physics Commons

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