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arXiv · 1106.2552

Universal phase structure of dilute Bose gases with Rashba spin-orbit coupling

Sarang Gopalakrishnan·Austen Lamacraft·Paul M. Goldbart
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Abstract

A Bose gas subject to a light-induced Rashba spin-orbit coupling possesses a dispersion minimum on a circle in momentum space; we show that kinematic constraints due to this dispersion cause interactions to renormalize to universal, angle-dependent values that govern the phase structure in the dilute-gas limit. We find that, regardless of microscopic interactions, (a) the ground state involves condensation at two opposite momenta, and is, in finite systems, a fragmented condensate; and (b) there is a nonzero-temperature instability toward the condensation of pairs of bosons. We discuss how our results can be reconciled with the qualitatively different mean-field phase diagram, which is appropriate for dense gases.

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Sarang Gopalakrishnan, Austen Lamacraft, Paul M. Goldbart. 2011-12-21. Universal phase structure of dilute Bose gases with Rashba spin-orbit coupling. https://doi.org/10.1103/physreva.84.061604

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