Microcavity exciton polariton systems can have a wide range of macroscopic quantum effects that may be turned into better photonic technologies. Polariton Bose-Einstein condensation and photon lasing have been widely accepted in the limits of low and high carrier densities, but identification of the expected Bardeen-Cooper-Schrieffer (BCS) state at intermediate densities remains elusive, as the optical-gain mechanism cannot be directly inferred from existing experiments. Here, using a microcavity with strong polarization selectivity, we gain direct experimental access to the reservoir absorption in the presence of polariton condensation and lasing, which reveals a fermionic gain mechanism underlying the polariton laser. A microscopic many-particle theory shows that this polariton lasing state is consistent with an open-dissipative-pumped system analog of a polaritonic BCS state.

中文翻译：

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Bardeen-Cooper-Schrieffer体制中的极化子激光

微腔激子极化子系统可以具有广泛的宏观量子效应，这些效应可以转化为更好的光子技术。在低和高载流子密度的限制下，极化子玻色-爱因斯坦凝聚和光子激射已被广泛接受，但是在中间密度下对期望的Bardeen-Cooper-Schrieffer（BCS）状态的识别仍然难以捉摸，因为无法获得光增益机制直接从现有实验中推论得出。在这里，使用具有强偏振选择性的微腔，我们在存在极化子凝聚和激射的情况下获得了直接访问储层吸收的实验方法，这揭示了极化子激光器下的铁离子增益机制。