State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser spectroscopy, Shanxi University, Taiyuan, 030006, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
Sci Rep. 2017 Sep 5;7(1):10568. doi: 10.1038/s41598-017-10686-3.
The coupling of ultracold fermions to a high-finesse optical cavity can result in novel many-body phenomena, and has attracted significant interests at present. Here we consider a realization of the Fermi-Dicke model with controllable parameters, based on a two-dimensional polarized degenerate Fermi gas coupled to an optical cavity. We analytically investigate the ground-state properties of such system under the mean-field approximation. We find the system can exhibit a rich phase diagram depending on the fermion-photon coupling strength and the atomic resonant frequency. Contrasting to the bosonic counterpart, a first-order quantum phase transition between the superradiant phase and the normal phase featuring two Fermi surfaces can occur for the weak atomic resonant frequency, and there is a unique mixed phase where this normal phase and the superradiant phase coexist. The experimental detection of our results is also discussed.
超冷费米子与高精细光学腔的耦合可以产生新的多体现象，目前引起了广泛关注。在这里，我们考虑了一种基于二维极化简并费米气体与光学腔耦合的可控制参数的费米-狄克模型的实现。我们在平均场近似下分析了该系统的基态性质。我们发现，系统可以根据费米子-光子耦合强度和原子共振频率展示出丰富的相图。与玻色子对应物不同，对于弱原子共振频率，超辐射相和具有两个费米面的正常相之间会发生一级量子相变，并且存在一个独特的混合相，其中正常相和超辐射相共存。我们还讨论了实验检测我们结果的可能性。
