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arXiv 1409.6485cond-mat.stat-mechcond-mat.quant-gas
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玻色-爱因斯坦凝聚体的临界润湿、一级润湿和预润湿相变

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

Bert Van Schaeybroeck, Joseph Indekeu

摘要:

吸附在光学壁上的玻色-爱因斯坦凝聚体的超低温二元混合物可以经历润湿相变,其中一种物质排除另一种物质与壁接触。有趣的是,虽然硬壁边界条件需要的润湿过渡是一阶的,使用Gross-Pitaevskii理论,我们表明,一阶润湿以及临界润湿时,可以发生一个现实的指数光学壁势(倏逝波)与有限的开启长度$λ$被假定。在$λ/ξ_i$的展开式中计算相关的表面过剩能,其中$ξ_i$是冷凝物$i$的愈合长度。实验上,润湿转变可以通过使用费什巴赫共振改变物种间散射长度$a_{12}$来最好地接近。在硬壁极限$λ\rightarrow 0$中,推导出预湿和一阶湿润相边界的精确结果。

英文摘要:

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 $λ$ is assumed. The relevant surface excess energies are computed in an expansion in $λ/ξ_i$, where $ξ_i$ 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, $λ\rightarrow 0$, exact results are derived for the prewetting and first-order wetting phase boundaries.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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