物理学报2024，Vol.73Issue(1)：60-68,9.DOI:10.7498/aps.73.20231243
基于二维磁光阱的增强型199Hg冷原子团制备
Enhanced production of 199Hg cold atoms based on two-dimensional magneto-optical trap
摘要
Abstract
Efficient preparation of cold atoms plays an important role in realizing precision measurement including optical lattice clocks(OLCs).Fast preparation of cold atoms reduces Dick noise by shortening dead time in a clock interrogation cycle,which improves the stability of OLCs.Here,we increase the loading rate of the three-dimensional magneto-optical trap(3D-MOT)in the ultra-high vacuum environment by utilizing the two-dimensional magneto-optical trap(2D-MOT)with a push beam,reduce the temperature of cold atoms with the compression-MOT technique which is implemented by reducing the detuning of 3D-MOT rapidly at the end of atom preparation,and realize the enhanced production of cold atoms for 199Hg OLCs.To achieve 3D-MOT and 2D-MOT of mercury atoms,a deep ultraviolet laser(DUVL)system composed of three DUVLs is developed with one working in lower power for frequency locking and the other two in high power for laser cooling.Such a configuration improves the long-term frequency stability and shows greater robustness than our previous system consisting of two DUVLs.To maximize the 3D-MOT loading rate,we orderly optimize the detuning and the magnetic field gradient of 3D-MOT and those of 2D-MOT as well as the detuning and the power of the push beam.After all parameters are optimized,we measure the maximum loading rate of 3D-MOT to be 3.1×105 s-1 and prepare cold atoms of 1.8×106 in 9 s.The loading rate is greatly enhanced by a factor of 51 by using 2D-MOT and the push beam.In order to improve the efficiency of transferring cold atoms from 3D-MOT to optical lattice,we use compression-MOT technique to reduce the temperature of cold atoms and produce cold 199Hg atoms which are about 45 μK,lower than the expected temperature of Doppler cooling theory.By achieving the high gain of the 3D-MOT loading rate under the ultra-high vacuum and reducing the temperature of cold atoms,this enhanced preparation of cold atoms based on 2D-MOT effectively shortens the preparation time of cold atoms and improves the transfer efficiency of optical lattice,which provides a significant scheme for efficiently preparing cold mercury atoms in other experiments.关键词
汞原子/光晶格钟/激光冷却/二维磁光阱Key words
mercury atom/optical lattice clock/laser cooling/two-dimensional magneto-optical trap引用本文复制引用
余泽鑫,刘琪鑫,孙剑芳,徐震..基于二维磁光阱的增强型199Hg冷原子团制备[J].物理学报,2024,73(1):60-68,9.基金项目
国家自然科学基金(批准号:11874371,91436105,12104474)、中国科学院战略性先导科技专项(批准号:XDB21030200)和上海市科技计划(批准号:22ZR1471000)资助的课题.Project supported by the National Natural Science Foundation of China(Grant Nos.11874371,91436105,12104474),the Strategic Pilot Science and Technology Project of the Chinese Academy of Science,China(Grant No.XDB21030200),and the Shanghai Science and Technology Program,China(Grant No.22ZR1471000). （批准号:11874371,91436105,12104474）
