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arXiv 0708.3167cond-mat.supr-concond-mat.other
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简谐势阱中不同原子种类的非对称费米超流体

Asymmetric Fermi superfluid with different atomic species in a harmonic trap

C. -H. Pao, shin-Tza Wu, S. -K. Yip

摘要:

本文利用平均场论和局域密度近似,研究了谐振势阱中两种费米子配对、浓度不等的稀费米子气体。我们发现该系统可以表现出超流壳结构夹在正常的费米子。当质量比大于某个临界值时,会出现这种超流壳结构,该临界值从弱耦合BCS区向强耦合BEC区逐渐增大。在强耦合BEC区域,超流相半径对质量比的敏感性较低,与等质量配对的情况相似。然而,较轻的剩余费米子比较重的费米子更容易与超流体核心混合。如果大多数费米子较轻,则可以发现部分极化的超流体,而如果它们较重,则仍然可以发现相分离。

英文摘要:

We study the dilute fermion gas with pairing between two species and unequal concentrations in a harmonic trap using the mean field theory and the local density approximation. We found that the system can exhibit a superfluid shell structure sandwiched by the normal fermions. This superfluid shell structure occurs if the mass ratio is larger then certain critical value which increases from the weak-coupling BCS region to the strong-coupling BEC side. In the strong coupling BEC regime, the radii of superfluid phase are less sensitive to the mass ratios and are similar to the case of pairing with equal masses. However, the lighter leftover fermions are easier to mix with the superfluid core than the heavier ones. A partially polarized superfluid can be found if the majority fermions are lighter, whereas phase separation is still found if they are heavier.

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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