超冷量子气体中的新奇局域激发模式

随着激光冷却技术的发展，超冷量子气体中玻色-爱因斯坦凝聚(BEC)终于得以实现。BEC是一种新兴的物质形态，被称为物质的“第五态”。对它的研究是目前一前沿和热点问题。. 本项目对BEC中存在的一些新奇局域激发模式进行理论研究，主要有Benard-von Karman涡街、带隙孤子、Hopf孤子等。针对多分量BEC系统，研究Benard-von Karman涡街的结构特征，以及各物理参量对涡旋结构的影响，分析涡旋演化的动力学机理和可能的实验观测，并与经典流体情形进行比较。对不同外势情形下BEC中高维带隙孤子的新型结构特征、动力学行为进行研究，分析其动力学不稳定性与能量不稳定性，并对实验观测进行一定理论指导。也将对三维情形下BEC系统中的Hopf孤子的结构特征及动力学性质进行一定探索研究，从而推动相关理论的发展。

With the development of laser cooling technology, the Bose-Einstein condensate (BEC) in ultra-cold quantum gas has finally been realized. BEC is a new form of matter, which is called the "fifth state" of matter. The research on it is a frontier and hot issue at present.. In this project, some novel localized excitation modes in BEC will be studied theoretically, including Benard-von Karman vortex street, bandgap soliton, Hopf soliton, etc. For the multi-component BEC system, the structural characteristics of the Benard-von Karman vortex street and the effects of various physical parameters on the vortex structure will be investigated systematically. The dynamical mechanism of the evolution of the vortex and possible experimental observations also will be analyzed. And we will compare the results with the classical fluid. The new structural characteristics and dynamic behavior of high-dimensional bandgap solitons in BEC under different external potentials will be studied. We will investigate their dynamic instability and energy instability properties. In addition, the structural characteristics and dynamic properties of Hopf solitons in the three-dimensional BEC system will be studied to promote the development of relevant theories.