Investigation of coherent manipulations in ultracold thermal and Bose-Einstein condensed molecular gases

该研究项目将从理论上研究通过光缔合产生分子玻色-爱因斯坦凝聚体。这使得建立在广泛的知识的光缔合和研究之间的相似性和差异的冷凝物和冷的热合奏。在分子形成中，原子间的关联变得重要，玻色-爱因斯坦凝聚的有效平均场描述变得无效。F. Masnou-Seeuws（CNRS Atomatoire Aimé Cotton，奥赛）考虑了由于两个碰撞原子的相互作用势的空间依赖性而产生的对相关性。这种方法应扩展到包括激光场的时间依赖性和非凝聚原子的存在。最优控制理论方法的R。Kosloff（耶路撒冷），然后可以用来优化创建一个稳定的分子玻色-爱因斯坦凝聚和预测光缔合速率。根据激光脉冲参数，分子形成和凝聚动力学的时间尺度可以分离。非凝聚态的原子可以被当作热浴来处理。概述的方法应适用于Na 2（钠二聚体）和Cs2（铯二聚体）的光缔合。应研究将该方法扩展至偶极分子，如杂碱二聚体。

The research project will theoretically investigate the creation of a molecular Bose-Einstein condensate by means of photoassociation. This allows to build on the extensive knowledge of photoassociation and to investigate similarities and differences between a condensate and a cold thermal ensemble. In molecule formation, correlations between atoms become important, and effective mean-field descriptions of Bose-Einstein condensates become invalid. A field theoretical approach currently developed in the group of F. Masnou-Seeuws (CNRS Laboratoire Aimé Cotton, Orsay), takes into account pair correlations due to the spatial dependence of the interaction potential of two colliding atoms. This approach shall be extended to include a time-dependence of the laser field and the presence of non-condensed atoms. The optimal control theory approach of the group of R. Kosloff (Hebrew University Jerusalem) can then be employed to optimize the creation of a stable molecular Bose-Einstein condensate and to predict photoassociation rates. Depending on the laser pulse parameters, the timescales of molecule formation and condensate dynamics can be separated. The noncondensed atoms can then be treated as a thermal bath. The outlined methodology shall be applied to photoassociation of Na2 (sodium dimer) and Cs2 (cesium dimer). The extension of the method to dipolar molecules such as heteronuclear alkali dimers shall be investigated.