BCS Wave-Function Approach to the BEC-BCS Crossover of Exciton-Polariton Condensates
BCS Wave-Function Approach to the BEC-BCS Crossover of Exciton-Polariton Condensates
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DOI：
10.1103/physrevlett.105.186402
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发表时间：
2010-10-26
影响因子：
8.6
通讯作者：
Yamamoto, Yoshihisa
中科院分区：
文献类型：
--
作者：
Byrnes, Tim;Horikiri, Tomoyuki;Yamamoto, Yoshihisa
用BCS波函数方法研究了激子-极化凝聚体的低密度区和高密度区之间的交叉。我们的方法是激子的BEC-BCS交叉理论的扩展，但包括腔光子场。该方法可以描述低密度极限和高密度极限，在低密度极限下，系统可以描述为激子-极化子的玻色-爱因斯坦凝聚(BEC)，而在高密度极限下，系统进入以光子为主的区域。与系统接近电子-空穴等离子体的激子BEC-BCS交叉不同，极化子高密度极限具有强关联的电子-空穴对。在中等密度下，存在一个具有类BCS性质的区域，峰值位于单重态对函数的非零动量。我们计算了预期的光致发光，并给出了几个交叉的实验特征。
The crossover between low and high density regimes of exciton-polariton condensates is examined using a BCS wave-function approach. Our approach is an extension of the BEC-BCS crossover theory for excitons, but includes a cavity photon field. The approach can describe both the low density limit, where the system can be described as a Bose-Einstein condensate (BEC) of exciton-polaritons, and the high density limit, where the system enters a photon-dominated regime. In contrast to the exciton BEC-BCS crossover where the system approaches an electron-hole plasma, the polariton high density limit has strongly correlated electron-hole pairs. At intermediate densities, there is a regime with BCS-like properties, with a peak at nonzero momentum of the singlet pair function. We calculate the expected photoluminescence and give several experimental signatures of the crossover.