Bose-glass, superfluid, and rung-Mott phases of hard-core bosons in disordered two-leg ladders

Article

关键词: LOW-ENERGY PROPERTIES;    FUNCTION MONTE-CARLO;    TONKS-GIRARDEAU GAS;    QUANTUM;    TRANSITION;    MODEL;   

DOI  :  10.1103/PhysRevB.83.245101

来源: SCIE

【 摘 要 】

By means of Monte Carlo techniques, we study the role of disorder on a system of hard-core bosons in a two-leg ladder with both intrachain (t) and interchain (t') hoppings. We find that the phase diagram as a function of the boson density, disorder strength, and t'/t is far from being trivial. This contrasts with the case of spinless fermions where standard localization arguments apply and an Anderson-localized phase pervades the whole phase diagram. A compressible Bose-glass phase always intrudes between the Mott insulator with zero (or one) bosons per site and the superfluid that is stabilized for weak disorder. At half-filling, there is a direct transition between a (gapped) rung-Mott insulator and a Bose glass, which is driven by exponentially rare regions where disorder is suppressed. Finally, by doping the rung-Mott insulator, a direct transition to the superfluid is possible only in the clean system, whereas the Mott phase is always surrounded by the a Bose glass when disorder is present. The phase diagram based on our numerical evidence is finally reported.

【 授权许可】

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