Collective effects in optically dense atomic clouds

本提案的目标是发展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个实验相关情况。目的是描述由辐射场介导的偶极-偶极耦合引起的涉及多原子量子相关的效应。所提出的工作的基础是一种可以通过将多体多模哈密顿量简化为有效的单原子方程来成功描述稠密气体中原子场相互作用的形式。该形式将用于研究以下问题：(i)将该形式应用于新颖的实验装置，例如表面磁阱（\atom chips”）上密集的准一维原子云；（ii）将形式主义推广到包括偶极-偶极量子相关；（iii）超辐射系统中的啁啾；（iv）对超和次辐射态的特别研究，并与少原子模型进行比较；(v)利用上述计算结果来解释和预测现实系统，特别是在原子芯片上的准一维超冷原子云和里德伯原子的超冷气体中。

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.