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 ultra-low-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.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 ultra-low-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.

arXiv:cond-mat/0410368Physical Review LettersNov 16, 200422 citations

Critical wetting, first-order wetting, and prewetting phase transitions in binary mixtures of Bose-Einstein condensates

Bert Van Schaeybroeck, Joseph O. Indekeu

An ultralow-temperature binary mixture of Bose-Einstein condensates adsorbed at an optical wall can undergo a wetting phase transition in which one of the species excludes the other from contact with the wall. Interestingly, while hard-wall boundary conditions entail the wetting transition to be of first order, using Gross-Pitaevskii theory we show that first-order wetting as well as critical wetting can occur when a realistic exponential optical wall potential (evanescent wave) with a finite turn-on length $\ensuremath{\lambda}$ is assumed. The relevant surface excess energies are computed in an expansion in $\ensuremath{\lambda}/{\ensuremath{\xi}}_{i}$, where ${\ensuremath{\xi}}_{i}$ is the healing length of condensate $i$ . Experimentally, the wetting transition may best be approached by varying the interspecies scattering length ${a}_{12}$ using Feshbach resonances. In the hard-wall limit, $\ensuremath{\lambda}\ensuremath{\rightarrow}0$, exact results are derived for the prewetting and first-order wetting phase boundaries.An ultralow-temperature binary mixture of Bose-Einstein condensates adsorbed at an optical wall can undergo a wetting phase transition in which one of the species excludes the other from contact with the wall. Interestingly, while hard-wall boundary conditions entail the wetting transition to be of first order, using Gross-Pitaevskii theory we show that first-order wetting as well as critical wetting can occur when a realistic exponential optical wall potential (evanescent wave) with a finite turn-on length $\ensuremath{\lambda}$ is assumed. The relevant surface excess energies are computed in an expansion in $\ensuremath{\lambda}/{\ensuremath{\xi}}_{i}$, where ${\ensuremath{\xi}}_{i}$ is the healing length of condensate $i$. Experimentally, the wetting transition may best be approached by varying the interspecies scattering length ${a}_{12}$ using Feshbach resonances. In the hard-wall limit, $\ensuremath{\lambda}\ensuremath{\rightarrow}0$, exact results are derived for the prewetting and first-order wetting phase boundaries.

arXiv:1409.6485Physical Review AJan 23, 201528 citations

THE INTERFACE POSITION OF A BOSE-EINSTEIN CONDENSATE MIXTURE RESTRICTED BY A HARD WALL IN THE DOUBLE-PARABOLA APPROXIMATION

Duy Thanh Pham, Thanh Hai Dang

In this study, we determine the interface position of a binary Bose-Einstein condensate mixture in the prewetting phase, confined by a hard wall, at absolute zero temperature. An approximate analytical result is obtained by employing the double-parabola approximation (DPA) to the quartic potential energy density within the Gross-Pitaevskii (GP) theory. The interface position depends on the control parameter and the chemical potential ratio. Our analytical result shows good agreement with numerical results, which indicates that the DPA is a reliable method. This study provides insights for experiments focused on observing the wetting transition of gases in the Bose-Einstein condensate phase.In this study, we determine the interface position of a binary Bose-Einstein condensate mixture in the prewetting phase, confined by a hard wall, at absolute zero temperature. An approximate analytical result is obtained by employing the double-parabola approximation (DPA) to the quartic potential energy density within the Gross-Pitaevskii (GP) theory. The interface position depends on the control parameter and the chemical potential ratio. Our analytical result shows good agreement with numerical results, which indicates that the DPA is a reliable method. This study provides insights for experiments focused on observing the wetting transition of gases in the Bose-Einstein condensate phase.

Dalat University Journal of ScienceJul 1, 20250 citations

i

. Experimentally, the wetting transition may best be approached by varying the interspecies scattering length

{a}_{12}

using Feshbach resonances. In the hard-wall limit, $\ensuremath{\lambda}\ensuremath{\rightarrow}0$, exact results are derived for the prewetting and first-order wetting phase boundaries.