Collective effects in optically dense atomic clouds

这项建议的目标是开发一种新的理论框架来描述致密原子样品中的相干和耗散过程，并将该理论应用于几种实验相关的情况。研究了辐射场介导的偶极-偶极耦合对多原子量子关联的影响，其基础是通过将多体多模哈密顿量简化为有效的单原子方程，成功地描述了稠密气体中原子-场相互作用。该方法将被应用于研究以下问题：（i）将该方法应用于新的实验装置，如表面磁阱上密集的准一维原子云（ii）将偶极-偶极量子关联推广到偶极-偶极量子关联;（iii）超辐射系统中的啁啾;（iv）超辐射态和次辐射态的特殊研究以及与少原子模型的比较;（v）使用上述计算的结果来解释和预测现实系统，特别是在原子芯片上准一维超冷原子云和里德伯原子超冷气体中。

The goal of this proposal is to develop a novel theoretical framework to describe both, coherent and dissipative processes in dense atomic samples, and to apply this theory in several experimentally relevant situations. The aim is to describe the effects involving multi-atom quantum correlations due to dipole-dipole coupling mediated by radiation fields.The basis for the proposed work is a formalism that can successfully describe atom-field interactions in dense gases by reducing a many-body multi-mode Hamiltonian to an effective single-atom equation. The formalism will be applied to investigate the following problems: (i) application of this formalism to novel experimental setups such as dense quasi-one dimensional atomic clouds on surface magnetic traps (\atom chips"); (ii) generalization of the formalism to include dipole-dipole quantum correlations; (iii) chirping in a superradiant system; (iv) special investigation of super- and subradiant states and comparison with few-atom models; (v) using the outcome of the above calculations to interpret and predict realistic systems, in particular in a quasi-1D ultracold atom cloud on an atom chip and an ultracold gas of Rydberg atoms.