Superfluid-Superfluid Phase Transitions in a Two-Component Bose-Einstein Condensate

A Kuklov
Nikolai Prokof'ev, University of Massachusetts - Amherst
Boris Svistunov, University of Massachusetts - Amherst

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This is the pre-published version harvested from ArXiv. The published version is located at http://prl.aps.org/abstract/PRL/v92/i3/e030403

Abstract

Depending on the Hamiltonian parameters, two-component bosons in an optical lattice can form at least three different superfluid phases in which both components participate in the superflow: a (strongly interacting) mixture of two miscible superfluids (2SF), a paired superfluid (PSF) vacuum, and (at a commensurate total filling factor) the super-counter-fluid (SCF) state. We study the universal properties of the 2SF-PSF and 2SF-SCF quantum phase transitions and show that (i) they can be mapped onto each other and (ii) their universality class is identical to the (d+1)-dimensional normal-superfluid transition in a single-component liquid. The finite-temperature 2SF-PSF(SCF) transitions and the topological properties of 2SF-PSF(SCF) interfaces are also discussed.