磁光阱中超冷钠-铯原子碰撞的实验研究  

Ultracold collisions in a dual species ^(23)Na-^(133)Cs magneto-optical trap

作　　者：徐润东[1,2] 刘文良[1,2] 武寄洲[1,2] 马杰[1,2] 肖连团[1,2] 贾锁堂[1,2] 

机构地区：[1]量子光学与光量子器件国家重点实验室,山西大学激光光谱研究所,物理电子工程学院,山西大学,太原030006 [2]极端光学协同创新中心,山西大学,太原030006

出　　处：《物理学报》2016年第9期48-54,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2012CB921603);长江学者和创新团队发展计划(批准号:IRT13076);基金委重大研究计划培育项目(批准号:91436108);国家自然科学基金(批准号:61378014,61308023,61378015,11434007);国家自然科学基金国家基础科学人才培养基金(批准号:J1103210);教育部新教师基金(批准号:20131401120012);山西省优秀青年学术带头人和山西省青年科技研究基金(批准号:2013021005-1)资助的课题~~

摘　　要：研究了磁光阱中异核超冷钠铯原子的碰撞机理,测量了超冷钠原子的碰撞损失率,得到了钠-铯原子的碰撞损失系数β_(Na-Cs)与钠原子俘获光强度之间的关系.利用多普勒模型计算了不同俘获光强度下的钠原子磁光阱的阱深,得到了临界光强的理论值,与实验结果符合得较好.The production and research of ultracold heteronuclear molecules have aroused the great interest recently.On the one hand,these molecules are extremely popular in experiments for exploring the collision dynamic behaviors in threshold,photoassociative spectrum and strong dipole-dipole interactions.On the other hand,ultracold polar molecules populated at deeply bound levels in the singlet ground state are the right candidates to investigate quantum memories for quantum simulation,and to study strongly interacting quantum degenerate gases.The precise knowledge of cold collision processes between two different types of alkali atoms is necessary for understanding and utilizing ultracold heteronuclear molecules,sympathetic cooling,and thus formation of two species BEC.The goal of the present investigation is to study the collisions between ultracold sodium atoms and cesium atoms.We systematically demonstrate simultaneously trapping ultracold sodium and cesium atoms in a dual-species magnetooptical trap（MOT）.The sodium atom trap loss rate coefficient β^（Na-Cs） is measured as a function of Na trapping laser intensity.At low intensities,the trap loss is dominated by ground-state hyperfine-changing collisions,while at high intensities,collisions involving excited atoms are more important.A strong interspecies collision-induced loss for Na atoms in the MOT is observed.In order to obtain the trap loss coefficient β^（Na-Cs） ,we proceed in two steps.First,the Cs repumping laser is blocked to avoid the formation of ultraold Cs atoms.The loading process of Na atoms is recorded when the Cs trapping laser is on.Second,the loading curves of the Na atoms are obtained as Cs atoms are present with the repumping laser beams.The total losses P_（Na） and P′_（Na） are acquired by fitting the two loading curves of trapped Naatoms.Thus,the trap loss coefficient β^（Na-Cs） can be derived from the difference between total losses P_（Na） and P′_（Na）divided by the density of the Cs atoms.The coefficient β^（

关 键 词：磁光阱 超冷钠原子 超冷铯原子 超冷碰撞 

分 类 号：O562[理学—原子与分子物理]