Preemptive vortex-loop proliferation in multicomponent interacting Bose--Einstein condensates

TL;DR

This paper investigates complex phase transitions in two-component Bose--Einstein condensates, revealing a novel preemptive vortex loop proliferation transition driven by topological defects, using analytical and large-scale Monte Carlo methods.

Contribution

It introduces the concept of a drag-induced preemptive vortex loop proliferation transition in multicomponent superfluids, supported by analytical vortex-matter arguments and numerical simulations.

Findings

Identification of a novel vortex-loop proliferation transition

Complex vortex behavior differs from single-component superfluids

Numerical evidence supporting the preemptive transition

Abstract

We use analytical arguments and large-scale Monte Carlo calculations to investigate the nature of the phase transitions between distinct complex superfluid phases in a two-component Bose--Einstein condensate when a non-dissipative drag between the two components is being varied. We focus on understanding the role of topological defects in various phase transitions and develop vortex-matter arguments allowing an analytical description of the phase diagram. We find the behavior of fluctuation induced vortex matter to be much more complex and substantially different from that of single-component superfluids. We propose and investigate numerically a novel drag-induced ``preemptive vortex loop proliferation'' transition. Such a transition may be a quite generic feature in many multicomponent systems where symmetry is restored by a gas of several kinds of competing vortex loops.