Polariton-polariton interaction beyond the Born approximation: A toy model study
Polariton-polariton interaction beyond the Born approximation: A toy model study
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DOI：
10.1103/physreva.102.063305
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发表时间：
2020-04
影响因子：
2.9
通讯作者：
Hui Hu;H. Deng;Xiaji Liu
中科院分区：
文献类型：
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作者：
Hui Hu;H. Deng;Xiaji Liu
我们采用一个具有接触相互作用的玩具模型来近似描述量子阱中电子与空穴之间的吸引力，并在平均场之外使用高斯对涨落理论，从理论上研究了微腔中常用的玻恩近似（即平均场）之外的极化子-极化子相互作用。我们得到了与密度或化学势无关的极化子-极化子相互作用强度，这是由与光子场的耦合引起的。我们表明，在我们的玩具模型中，量子涨落导致极化子-极化子相互作用强度降低约2倍。结合对强光-物质耦合下$ 15 $激子近似的修正，我们发现，如果我们的玩具模型可以定性地模拟GaAs量子阱中的极化子相互作用，那么在典型实验条件下，在广泛使用的理论中，极化子-极化子相互作用强度被高估了3倍。我们将我们的预测与最近的测量结果进行了比较，并认为对极化子-极化子相互作用强度的超出生近似效应对于定量理解Estrecho等人的实验数据至关重要。[j].生物工程学报，2016,31(5):391 - 391。
We theoretically investigate the polariton-polariton interaction in microcavities beyond the commonly used Born approximation (i.e., mean field), by adopting a toy model with a contact interaction to approximately describe the attraction between electrons and holes in quantum well and by using a Gaussian pair fluctuation theory beyond mean field. We obtain a density or chemical potential independent polariton-polariton interaction strength even in two dimensions, which result from coupling to the photon field. We show that quantum fluctuations lead to about a factor of 2 reduction in the polariton-polariton interaction strength within our toy model. Together with corrections to the $1s$ exciton approximation at very strong light-matter coupling, we find the polariton-polariton interaction strength under typical experimental conditions is overestimated by a factor of 3 in the widely used theories, if our toy model can qualitatively simulate the polariton interaction in GaAs quantum wells. We compare our prediction with the most recent measurement and argue that the beyond-Born-approximation effect to the polariton-polariton interaction strength is crucial for a quantitative understanding of the experimental data by Estrecho et al. [Phys. Rev. B 100, 035306 (2019)].