超冷^(85)Rb^(133)Cs分子转动态碰撞特性研究  

Studying on Collision Characteristics of Ultracold ^(85)Rb^(133)Cs Molecules in the Rotational States

作　　者：陈一瑶 马伟鑫 姬中华[1,2] 梅锋 赵延霆 贾锁堂[1,2] CHEN Yi-yao;MA Wei-xin;JI Zhong-hua;MEI Feng;ZHAO Yan-ting;JIA Suo-tang(State Key Laboratory of Quantum Optics and Quantum Optics 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量子光学与光量子器件国家重点实验室,山西太原030006 [2]山西大学极端光学协同创新中心,山西太原030006

出　　处：《量子光学学报》2024年第1期61-68,共8页Journal of Quantum Optics

基　　金：国家自然科学基金重点项目(12034012);国家自然科学基金面上项目(12074231;12274272)。

摘　　要：使用损耗光谱技术测量了直接光缔合制备的X^(1)Σ^(+)(v=0)振动基态超冷^(85)Rb^(133)Cs分子的转动态分布,使用微波脉冲技术操控了超冷^(85)Rb^(133)Cs分子转动态布居转化,对基态超冷^(85)Rb^(133)Cs分子最低振动态上纯转动态和混合转动态的碰撞特性进行了研究。具体地测量了^(85)Rb^(133)Cs分子分别处于X^(1)Σ^(+)(v=0,J=1)转动态、X^(1)Σ^(+)(v=0,J=2)转动态以及这两个转动态形成的混合态这三种情况下的分子布居演化,引入速率方程来描述损耗过程中分子的动力学过程并获得分子非弹性碰撞系数,实验发现转动混合态的碰撞系数高于纯转动态碰撞系数,造成这种差异的原因主要来自于相邻转动态之间的偶极—偶极相互作用。本工作为理解超冷极性分子非弹性碰撞机制、制备低温高密度超冷极性分子提供了重要参考。The study of collision of ground-state ultracold polar molecules,in particular the collision properties of two-body exchange of non-reactive molecules,is of great significance for understanding the inelastic collision of molecules,for obtaining the molecular samples with long-lived,stable chemical properties and degenerate quantum states,and carrying out moleculesbased applications.Our previous work[Phys.Chem.Chem.Phys.,20,4893(2018)]has achieved the short-range photo-association preparation and optical dipole capture of ^(85)Rb^(133)Cs molecules in the lowest vibrational state,and have measured the inelastic collision coefficients of ^(85)Rb^(133)Cs with ^(85)Rb and ^(133)Cs atoms.However,the above works have not realized the research on the collision characteristics of molecules in rotational dynamics.In this paper,the collision characteristics of different rotational dynamics on the lowest vibrational state of ^(85)Rb^(133)Cs molecule have been studied.In particular,the population of rotational states in the ground state ultracold ^(85)Rb^(133)Cs molecules prepared by directly photoassociation was measured by loss spectroscopy.The transformation of population of rotational states in the ultracold ^(85)Rb^(133)Cs molecules was controlled by microwave pulse technique.The collision characteristics of pure and mixed states in the lowest vibrational ground state of ultracold ^(85)Rb^(133)Cs molecules were studied.The evolution of population of ^(85)Rb^(133)Cs molecules is measured in three cases of X^(1)Σ^(+)(v=0,J=1),X^(1)Σ^(+)(v=0,J=2)and the mixed state formed by the two rotational states.The rate equation is introduced to describe the molecular dynamics in the loss process and the molecular inelastic collision coefficient is obtained.The experimental results show that the collision coefficient of the rotational mixed state is higher than the pure rotational state,which is mainly caused by the dipole-dipole interaction between the neighboring rotational states.The work provides an important reference for under

关 键 词：超冷极性分子 光缔合 转动态 非弹性碰撞 

分 类 号：O561[理学—原子与分子物理]