高偏置磁场下磁场空间分布对玻色爱因斯坦凝聚体自由飞行的影响  

Effect of Magnetic Field Spatial Distribution on Free Flight of Bose-Einstein Condensates under High Bias Magnetic Field

作　　者：王星宇 师振莲 李子亮 顾正宇 王鹏军[1] 张靖[1] WANG Xing-yu;SHI Zhen-lian;LI Zi-liang;GU Zheng-yu;WANG Peng-jun;ZHANG Jing(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学光电研究所,量子光学与光量子器件国家重点实验室,山西太原030006

出　　处：《量子光学学报》2022年第1期8-17,共10页Journal of Quantum Optics

基　　金：国家重点研发计划(2016YFA0301602,2018YFA0307601);国家自然科学基金(92065108,12034011)。

摘　　要：通过超冷原子的空间自由飞行来获取原子云在动量空间的信息,是超冷原子实验研究中一个重要的探测手段。磁Feshbach共振调控相互作用的超冷原子,需要高偏置磁场下空间自由飞行来获得相互作用能的信息,因此磁场的空间均匀分布对原子自由飞行会产生重要影响。本文对两种绕制的线圈进行了数值模拟,计算了在亥姆霍兹组态下的磁场分布产生,并实验研究了钠原子玻色爱因斯坦凝聚体在不同磁场分布下的自由飞行展开,分析给出了影响自由飞行展开原子密度的磁场线圈参数,为今后设计磁Feshbach共振线圈提供了重要依据。Free time-of-flight expansion of ultracold atoms is an important method to obtain the information of atomic cloud in the momentum space. Magnetic Feshbach resonance manipulates the interaction between atoms, therefore it requires free time-offlight expansion under high bias magnetic field to obtain the information of interaction energy. Therefore, the spatial distribution of magnetic field has an important influence on the free time-of-flight expansion of atoms. In this paper, we construct two kinds of magnetic coils, and calculate the magnetic field distribution under Helmholtz configuration and study the free time-of-flight expansion of sodium atoms Bose-Einstein condensate. The magnetic field coil parameters affecting the shape and size of atomic cloud after the free time-of-flight expansion are analyzed and discussed. This work provides an important suggestion for designing magnetic Feshbach resonance coils in the future.

关 键 词：吸收成像 数值模拟 BEC纵横比 

分 类 号：O469[理学—凝聚态物理]