关键词: Rydberg原子, 电磁感应透明, 自组织结构

Abstract:

In this study, light propagation and electromagnetically induced transparency(EIT) in cold Rydberg atomic gas were theoretically investigated, using an inhomogeneous coupling beam. By virtue of EIT, the strong long-range atom-atom interactions in Rydberg states are mapped to light fields, resulting in strong photonic interaction. In previous studies, the coupled optical field was considered as spatially uniform and constant, with the interaction of the optical field possessing potential energy with spatial translation invariance. In the case of repulsive atomic interactions, when the intensity of the probe light field exceeds a critical threshold, the system undergoes a first-order phase transition because of the instability of the roton mode in momentum space, leading to self-organization of the system into optical patterns. However, in recent experiments, the spatial distribution of coupled light has often been nonuniform, and this nonuniformity can destroy the spatial translation invariance of the system. Our calculations show that when considering a large beam waist with coupling, the system can still self-organize into optical pattern structures at low atomic densities. However, as the atomic density increases, the edges of the patterns can be disrupted due to an increase in nonuniform excitation. The results of this study not only contribute to the development of Rydberg nonlinear optics but also have potential applications in the design of novel nonlinear optical devices in many-body systems.

Key words: Rydberg atom, electromagnetically induced transparency, self-organizing structure