Exotic phase separation and phase diagrams of a Fermi-Fermi mixture in a trap at finite temperature
Exotic phase separation and phase diagrams of a Fermi-Fermi mixture in a trap at finite temperature
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有限温度下陷阱中费米-费米混合物的奇异相分离和相图
DOI：
10.1103/physreva.87.041601
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发表时间：
2013-04-11
影响因子：
2.9
通讯作者：
Chen, Qijin
中科院分区：
文献类型：
--
作者：
Wang, Jibiao;Guo, Hao;Chen, Qijin
粒子数和质量的不平衡对双组分费米气体中的配对和超流现象有很强的影响。在这里，我们提出的原子费米气体的相图，因为他们经历BCS-玻色-爱因斯坦凝聚（BEC）交叉与人口和质量的不平衡，使用配对波动理论。我们着重研究了有限温度和陷阱效应，重点是$^{6}$Li和$^{40}$K原子的混合。结果表明，在BEC体系中存在奇异的相分离，在BCS体系和么正体系中，特别是当轻组分占大多数时，在低温下存在具有超流或赝能隙的中心壳层结构.当质量不平衡超过一定的阈值时，就会出现这种类似贝壳的结构。我们的结果与未来的实验有关的$^6$Li-$^{40}$K混合物和可能的其他费米-费米混合物。
The pairing and superfluid phenomena in a two-component Fermi gas can be strongly affected by the population and mass imbalances. Here we present phase diagrams of atomic Fermi gases as they undergo BCS--Bose-Einstein condensation (BEC) crossover with population and mass imbalances, using a pairing fluctuation theory. We focus on the finite temperature and trap effects, with an emphasis on the mixture of $^{6}$Li and $^{40}$K atoms. We show that there exist exotic types of phase separation in the BEC regime as well as sandwich-like shell structures at low temperature with superfluid or pseudogapped normal state in the central shell in the BCS and unitary regimes, especially when the light species is the majority. Such a sandwich-like shell structure appear when the mass imbalance increases beyond certain threshold. Our result is relevant to future experiments on the $^6$Li--$^{40}$K mixture and possibly other Fermi-Fermi mixtures.