Extraordinary wetting phase diagram for mixtures of Bose-Einstein condensates

TL;DR

This paper predicts a unique wetting phase diagram for Bose-Einstein condensate mixtures, revealing novel phase transition behaviors at ultralow temperatures, with potential for experimental verification using optical methods.

Contribution

It introduces a theoretical prediction of wetting phase transitions in BEC mixtures, highlighting unusual critical prewetting and non-tangential coexistence lines.

Findings

Wetting phase transitions can occur in BEC mixtures via Feshbach resonances.

Prewetting transition is critical, not first order, contrary to expectations.

The wetting phase diagram exhibits extraordinary features at ultralow temperatures.

Abstract

The possibility of wetting phase transitions in Bose-Einstein condensed gases is predicted on the basis of Gross-Pitaevskii theory. The surface of a binary mixture of Bose-Einstein condensates can undergo a first-order wetting phase transition upon varying the interparticle interactions, using, e.g., Feshbach resonances. Interesting ultralow-temperature effects shape the wetting phase diagram. The prewetting transition is, contrary to general expectations, not of first order but critical, and the prewetting line does not meet the bulk phase coexistence line tangentially. Experimental verification of these extraordinary results is called for, especially now that it has become possible, using optical methods, to realize a planar "hard wall" boundary for the condensates.