当前位置: X-MOL 学术Phys. Rev. Research › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Finite-temperature spin dynamics of a two-dimensional Bose-Bose atomic mixture
Physical Review Research ( IF 3.5 ) Pub Date : 2021-02-18 , DOI: 10.1103/physrevresearch.3.013161
Arko Roy , Miki Ota , Alessio Recati , Franco Dalfovo

We examine the role of thermal fluctuations in uniform two-dimensional binary Bose mixtures of dilute ultracold atomic gases. We use a mean-field Hartree-Fock theory to derive analytical predictions for the miscible-immiscible transition. A nontrivial result of this theory is that a fully miscible phase at T=0 may become unstable at T0, as a consequence of a divergent behavior in the spin susceptibility. We test this prediction by performing numerical simulations with the stochastic (projected) Gross-Pitaevskii equation, which includes beyond mean-field effects. We calculate the equilibrium configurations at different temperatures and interaction strengths and we simulate spin oscillations produced by a weak external perturbation. Despite some qualitative agreement, the comparison between the two theories shows that the mean-field approximation is not able to properly describe the behavior of the two-dimensional mixture near the miscible-immiscible transition, as thermal fluctuations smoothen all sharp features both in the phase diagram and in spin dynamics, except for temperature well below the critical temperature for superfluidity.

中文翻译:

二维Bose-Bose原子混合物的有限温度自旋动力学

我们研究了热波动在稀释的超冷原子气体的均匀二维二元Bose混合物中的作用。我们使用均场Hartree-Fock理论来得出可混溶-不可混溶转变的分析预测。这一理论的重要成果是,在Ť=0 可能会变得不稳定 Ť0,这是自旋磁化率行为不同的结果。我们通过使用随机(预测的)Gross-Pitaevskii方程进行数值模拟来测试此预测,其中包括超出平均场的影响。我们计算了在不同温度和相互作用强度下的平衡构型,并模拟了由弱外部扰动产生的自旋振荡。尽管有一些定性的共识,但两种理论之间的比较表明,均值场近似无法正确描述二维混合物在混溶-非混溶转变附近的行为,因为热波动会平滑相中所有的尖锐特征图和自旋动力学,除了温度远低于超流的临界温度。
更新日期:2021-02-18
down
wechat
bug