偶极旋量玻色－爱因斯坦凝聚中周期性驱动的自旋动力学

含有磁偶极相互作用的旋量玻色-爱因斯坦凝聚是冷原子和冷分子气体领域非常热门的课题。该体系的自旋动力学，尤其是周期性外场驱动的动力学，是一个崭新的、尚待探索的领域。本项目拟首先采用平均场理论，在单模近似下研究偶极旋量玻色-爱因斯坦凝聚中原子自旋的动力学，理解偶极相互作用、自旋散射相互作用、和周期性外加磁场等对体系自旋动力学的影响。然后采用大规模数值模拟的方法，研究体系在超越单模近似条件下的非平衡动力学。最后在单模近似下采用二次量子化理论和数值计算方法研究偶极旋量玻色-爱因斯坦凝聚中多自旋体系的量子动力学，特别是体系的量子多体效应，并利用偶极相互作用高效地实现该体系的自旋压缩态，从而为发展基于偶极旋量玻色-爱因斯坦凝聚的精密测量，比如高空间分辨率的磁力计，提供理论基础。

Dipolar spinor Bose-Einstein condensate with magnetic dipolar interaction is a hot topic in ultracold atomic and molecular gases. The spin dynamics of the system, particularly the periodically driven spin dynamics, is a new and unexplored area. In this project, we first investigate the spin dynamics of the dipolar spinor condensate, focusing on the effects of the magnetic dipolar interaction, the spin-dependent interaction, and the external magnetic field on the system’s dynamics, under the single spatial mode approximation in the mean field theory. We then investigate the non-equilibrium dynamics of the system beyond the single mode approximation with the aid of large-scale numerical calculations. Finally, by employing the single mode approximation and the second quantization methods, we numerically investigate the quantum spin dynamics in the dipolar spinor condensates, with the emphasis of the many-body effects, and utilize the dipolar interaction to realize efficiently the spin squeezed state in the system, which provides the theoretical supports for the development of precision measurement based on dipolar spinor condensates, such as high spatial-resolution magnetometer.