利用三维光晶格技术实现铯原子冷却的实验研究  

3D optical lattices cooling of ultracold Cs atoms

作　　者：王宏亮[1,2] 冯国胜[1] 李玉清[1] 武寄洲[1,3] 马杰[1,3] 肖连团[1,3] 贾锁堂[1,3] 

机构地区：[1]山西大学物理电子工程学院激光光谱研究所量子光学与光量子器件国家重点实验室,太原030006 [2]晋城职业技术学院机械电子工程系,晋城048026 [3]山西大学极端光学协同创新中心,太原030006

出　　处：《中国科学：物理学、力学、天文学》2017年第6期53-58,共6页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家重点基础研究发展计划(编号:2012CB921603);教育部长江学者和创新团队发展计划(编号:IRT13076);国家自然科学基金重大研究计划培育项目(编号:91436108);国家自然科学基金(编号:61378014;61308023;61378015;11434007);教育部新教师基金(编号:20131401120012)资助

摘　　要：激光冷却原子是超冷原子分子物理实验的基础,在精密测量、量子模拟等研究中具有重要的意义.为了获得温度更低,密度更高的超冷铯原子样品作为制备超冷基态铯分子的起点,本文实验展示了一种利用三维光晶格装载实现超冷铯原子温度进一步降低的方法,有效克服了磁光阱中超冷原子辐射光子自吸收引起的加热问题.在标准的磁光阱系统中获得超冷铯原子的基础上,利用压缩磁光阱技术提高超冷铯原子的密度.通过四束激光构建三维光晶格,实现超冷铯原子的高效装载,采用飞行时间法测量了原子的温度,观察到温度由~6 0.0μK降低至~1 1.6μK的冷却结果.同时研究了光晶格激光的频率与原子装载数目的关系,发现在负失谐1 5.5GHz时光晶格装载效率最高.同时,本文研究了利用光晶格减小超冷原子辐射光子自吸收引起的加热问题,对于进一步降低铯原子温度的研究具有深远的意义.Laser cooling of atoms is the basis of researches on ultracold atoms and molecules. It is of great importance in the study of precision measurement and quantum simulation, etc. In order to obtain ultracold cesium atomic sample with a lower temperature and a higher density, as the starting point to create ultracold cesium ground state molecules, we demonstrate in this article a method which effectively overcomes the heating from the reabsorption of scattered light in magneto-optical trap to further reduce the ultracold atomic temperature by loading atoms into a 3D optical lattices. Based on obtaining the ultracold Cs atoms in a standard magneto-optical trap, we use the compressed magneto-optical trap technology to increase ultracold Cs atomic density. Efficient loading ofultracold Cs atoms is achieved by 3D optical lattices which constructed by four lasers; the temperature of the atoms is measured by time-of-flight method. We observed the cooling result that the temperature drops from -60.0μK to -11.6 μK. We also explore the dependence of the atom numbers in the lattice on the frequency of lattice lasers, and lead to the conclusion that the loading rate of the optical lattices reaches its maximum when the lattices laser＇s detuning is -15.5 GHz. In the meantime, this paper investigates the use of optical lattice to suppress the heating of the ultracold atoms due to the radiation photons, in this sense, our research has far-reaching significance. Our scheme is advantageous due to its relaxed starting temperature requirement, meaning that 3D DRSC can be directly accomplished in a standard single cell vapour-loaded MOT without reliance on any additional devices such as a Zeeman slower.

关 键 词：原子冷却 光晶格 磁光阱 

分 类 号：O562[理学—原子与分子物理]