微光学腔内单原子的俘获及其耦合强度的精确调控  

Trapping of single atom and precise control of its coupling strength in micro-optical cavity

作　　者：闫玮植 范青 杨鹏飞 李刚[1,2] 张鹏飞[1,2] 张天才[1,2] Yan Wei-Zhi;Fan Qing;Yang Peng-Fei;Li Gang;Zhang Peng-Fei;Zhang Tian-Cai(State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Opto-Electronics,Shanxi University,Taiyuan 030006,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)

机构地区：[1]山西大学光电研究所,量子光学与光量子器件国家重点实验室,太原030006 [2]山西大学,极端光学省部共建协同创新中心,太原030006

出　　处：《物理学报》2023年第11期214-220,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:U21A6006,U21A20433,11974223,11974225,12104277,12104278);国家重点研发计划(批准号:2021YFA1402002);山西省“1331工程”重点学科建设基金资助的课题.

摘　　要：通过在长度为336μm的光学法布里-珀罗腔内构建单个微尺度光学偶极阱,实现了腔内单个原子的俘获,俘获寿命为(2.60±0.18)s,从而实现了稳定的单原子与光学腔强耦合的腔量子电动力学系统.通过腔的透射光场能够实现光学阱中单原子俘获事件的检测,准确率为98.5%.实验通过精确控制俘获的单原子位置实现了单原子与腔模耦合强度在三维方向的精确调控,测量了不同耦合强度下的单原子真空拉比分裂谱.Cavity quantum electrodynamic system with strongly coupled single atoms provides a good platform for studying quantum information processing,quantum simulation,quantum network,and distributed quantum computing.Cooling and trapping single atoms is a crucial technique in the quantum technology.At present,in a high-finesse cavity with finite space,cooling and trapping single atoms is a big challenge,even though it is a mature technique for free space.Great efforts have been made to cool and trap single atoms inside a cavity,and for a trapped atom its lifetime has reached as long as tens of seconds.Developing a more flexible method of cooling and trapping single atoms in a cavity is still essential for a strongly coupled cavity quantum electrodynamic system.In this work,we demonstrate experimentally that a single cesium atom in a cavity can be trapped by utilizing a single optical tweezer settled in cavity mode,and its lifetime is(2.60±0.18)s.The experiment is carried out in a Fabry-Perot cavity,which is assembled by two concave mirrors each with a curvature radius of 100 mm,and cavity length of 335μm.The concave surfaces are highly reflective,and the cavity has a finesse of 6.1×104.The 1080 nm optical tweezer with a waist of 2μm is formed by an achromatic lens group with a numerical aperture of 0.4.At first,the precooled atomic assemble released from the magnetooptical trap(MOT)is transferred into cavity mode by an optical dipole trap with a waist of 36μm.Then,one of the successfully transferred atoms is captured by the optical tweezer with the aid of cavity cooling mechanism.A blue detuned cavity locking laser is used as a standing-wave optical trap along the cavity axis.The signal of successfully trapped one atom is obtained by recording transmission of the cavity that will decrease owing to the strong coupling induced vacuum Rabi splitting.Finally,we demonstrate the precise manipulation of the atom-cavity coupling strength,which is achieved by scanning the position of the trapped atom step by step by using a

关 键 词：腔量子电动力学 单原子 偶极阱 强耦合 

分 类 号：O413.2[理学—理论物理]