平均场框架下两分量玻色-爱因斯坦凝聚中集体激发的阻尼  

Damping of Collective Excitations in Two-Component Bose-Einstein Condensates Using Mean-Field Description

作　　者：热依扎·塔斯恒 魏蔚[1] 周昱 马晓栋[1] Reyza Tasheng;Wei Wei;Zhou Yu;Ma Xiaodong(Xinjiang Key Laboratory for Luminescence Minerals and Optical Functional Materials,School of Physics and Electronic Engineering,Xinjiang Normal University,Urumchi 830054,Xinjiang,China;School of Science,Jiangsu University of Science and Technology,Zhenjiang 212003,Jiangsu,China)

机构地区：[1]新疆师范大学物理与电子工程学院,新疆发光矿物与光功能材料研究重点实验室,新疆乌鲁木齐830054 [2]江苏科技大学理学院,江苏镇江212003

出　　处：《光学学报》2023年第10期253-268,共16页Acta Optica Sinica

基　　金：国家自然科学基金(10864006,11264039);新疆维吾尔自治区高校科研计划重点项目(XJED2010141);新疆师范大学博士科研启动基金(XJNUBS1805);新疆师范大学“物理学”特色专业和新疆师范大学“物理学”重点学科资助课题。

摘　　要：研究两分量玻色-爱因斯坦凝聚中集体激发的阻尼,该阻尼包括朗道和巴利耶夫两种机制。采用哈特利-福特-波戈留波夫平均场理论,基于单分量系统理论,构建了两分量系统的理论框架,严格按照单分量系统理论推导公式,并且分析两分量系统和单分量系统在理论框架构建上的主要差别。以理想的能级连续的均匀系统朗道阻尼为例进行半经典近似计算,展示粒子相互作用细节,说明所提理论的物理意义和应用方法。在计算过程中,通过无量纲阻尼函数分析朗道阻尼与温度的依赖关系,分析对阻尼有贡献的准粒子跃迁,包括同类型准粒子之间和不同类型准粒子之间的各种情况,并通过误差函数分析不同能量范围的准粒子跃迁对阻尼的贡献。Objective The damping of collective excitations in two-component Bose-Einstein condensates(BECs)is studied.The damping includes Landau and Baliaev mechanisms.Elementary excitation in BECs is the basic subject of statistical physics and condensed matter physics.With the development of Feshbach resonance technology in ultra-cold atomic gases and the use of highly controllable ultra-cold quantum systems,significant progress has been made in related research.The attenuation of collective excitation amplitude is called damping,which is generated by the interaction between particles.Damping is an important feature of low-energy collective excitation in the BEC experiment.Accurate calculation of damping is very important for understanding the essence of quantum multi-body physics.Since the damping of collective excitation is one of the long-term and important topics in the study of quantum multi-body physics,and the two-component BEC system has rich physical properties,the application of Hartree-Fock-Bogoliubov(HFB)mean-field theory in this paper is extended,so as to provide ideas for the smooth development of related research work.Methods HFB mean-field theory is used,and the theoretical framework of the two-component system is constructed based on the original work of the one-component system theory.The collective excitation damping formula is derived strictly according to the original work method,including the Bogoliubov-de Gennes equations of non-condensed quasiparticles obtained by diagonalizing the giant canonical Hamiltonian.The three-mode coupling matrix element describing the interaction between particles is obtained by commutation calculation and Fourier transform of normal and abnormal quasi-particle distribution function motion equations,and the relation for the perturbed eigenfrequency and the damping rate of collective excitation are obtained by Fourier transform of collective excitation motion equations.Landau damping of collective excitation in a continuous two-component BEC homogeneous system with an id

关 键 词：量子光学 元激发 无量纲阻尼函数 误差函数 波戈留波夫变换 傅里叶变换 

分 类 号：O469[理学—凝聚态物理]