自旋-轨道耦合玻色凝聚体中的自旋频谱动力学响应  

Dynamical response of spin frequency spectrum in spin-orbit coupled Bose-Einstein condensate

作　　者：樊景涛 贾锁堂[1,2] FAN Jingtao;JIA Suotang(State Key Laboratory of Quantum Optics Technologies and Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学激光光谱研究所,光量子技术与器件全国重点实验室,太原030006 [2]山西大学,极端光学协同创新中心,太原030006

出　　处：《物理学报》2025年第9期266-276,共11页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2022YFA1404201);国家自然科学基金(批准号:12174233);山西省“1331工程”重点学科建设计划资助的课题.

摘　　要：基于自旋-轨道耦合玻色凝聚体,提出了一种凝聚体的自旋频谱对外场调控参数的动力学响应效应.该效应由对凝聚体的快速晃动和外加的迅变塞曼场来驱动.研究发现,自旋频谱的谱峰对外场驱动参数呈现出简单的线性关系.通过对模型作适当近似和简化,本文给出了该线性关系的解析关系式.同时,基于Gross-Pitaevskii方程对系统的动力学演化做了数值计算,数值结果与解析表达式符合得很好.另外,本文还进一步探究了自旋频谱对外场驱动响应的物理本质,发现该效应来源于不同自旋-轨道态之间的量子干涉,可以利用量子多臂干涉仪的图像来理解其内涵.文章的最后对方案的实验可行性及相关参数进行了讨论与估计.本文的结果在量子控制和量子计量学等领域有潜在价值.Dynamical characteristics of internal and external states of a Bose-Einstein condensate are generally different and independent,thus requiring different experimental manipulation techniques.The spin-orbit coupling recently achieved in Bose-Einstein condensates essentially connects spin and motion degree of freedom,endowing spin states with the ability to respond to orbital manipulation,and vice versa.In this work,a dynamical response effect,induced by simultaneously manipulating the internal and external states of a spinorbitcoupled Bose-Einstein condensate,is predicted.Here,the“simultaneously manipulating the internal and external states”means that the driving field combines the Zeeman field applied to the internal state of the atom and the orbital potential affecting the external states of the atom.Specifically,the Bose-Einstein condensate is assumed to be activated by an abruptly applied Zeeman field and a sudden shake of the trapping potential.After some reasonable simplification and approximation of the model(i.e.neglecting the inter-atomic interactions and modelling the shake of the trapping potential by a short time-dependent pulse),an analytical relationship connecting spin frequency spectrum and the parameters of the driving fields is derived.The numerical calculations based on directly integrating the Gross-Pitaevskii equation are in good agreement with the results from the analytical relationship.The physical origin of the predicted spin dynamical response can be traced back to the quantum interference among different spin-orbit states.Due to the fact that a series of characteristic parameters of the condensate can be manifested in the spin frequency spectrum,the dynamical response effect predicted here provides a candidate method for determining and calibrating various system parameters by measuring the spin frequency spectrum.

关 键 词：玻色-爱因斯坦凝聚 自旋-轨道耦合 超冷量子气体 自旋频谱 

分 类 号：O469[理学—凝聚态物理]