Light–matter interaction in cold atomic ensembles is one of the central topics in modern quantum and atomic optics with important applications in various quantum technologies. The collective response of dense atomic gases under light excitation depends crucially on the spatial distribution of atoms and the geometry of the ensemble. We analyze near-resonant light transmission in two-dimensional dense ultracold atomic ensembles with short-range positional correlations. Based on coupled-dipole simulations, we show that the collective effects, manifested as notable shifts of transmission resonance frequency and considerable modification of optical depths, are influenced strongly by positional correlations. Mean-field theories such as the Lorentz–Lorenz relation are not capable of describing such collective effects. We also investigate the statistical distribution of eigenstates and provide a connection between the transmission spectra and eigenstate distribution by utilizing the population weighted detuning and decay rate of all eigenstates. We further demonstrate the intricate interplay between dipole–dipole interactions and positional correlations by increasing the number densities of atoms.

中文翻译：

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具有短程位置相关性的二维致密冷原子介质中的近共振光传输

冷原子集合体中的光-物质相互作用是现代量子和原子光学的中心主题之一，在各种量子技术中都有重要的应用。密集的原子气体在光激发下的集体响应主要取决于原子的空间分布和整体的几何形状。我们分析具有短程位置相关性的二维密集超冷原子团中的近共振光传输。基于耦合偶极子模拟，我们表明，位置相关性强烈地影响了集体效应，这些效应表现为传输共振频率的明显偏移和光学深度的显着变化。诸如洛伦兹-洛伦茨（Lorentz-Lorenz）关系之类的均值理论无法描述这种集体效应。我们还研究了本征态的统计分布，并利用所有本征态的总体加权失谐和衰减率，在透射光谱与本征态分布之间建立了联系。通过增加原子数的密度，我们进一步证明了偶极-偶极相互作用与位置相关之间的复杂相互作用。