两个真空光悬浮纳米粒子间的光诱导偶极相互作用  

Light-induced Dipole-dipole Interaction of Two Optically Levitated Nanoparticles in a Vacuum

作　　者：王彦 高晨力 闫江伟 于旭东[1,2] 张靖 WANG Yan;GAO Chen-li;YAN Jiang-wei;YU Xu-dong;ZHANG Jing(The 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,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44-52,共9页Journal of Quantum Optics

基　　金：国家自然科学基金(61975101;11234008;61571276)。

摘　　要：光悬浮微纳米粒子系统是研究多体物理的重要平台,但是以往相关研究大多集中在液体环境中。真空光悬浮由于其显著的优势,近年来受到了广泛关注。本文利用两个紧聚焦光场单独捕获两个纳米粒子,在真空环境下,实验研究了粒子间由于散射光诱导的偶极相互作用。在不同捕获光偏振条件下,通过调控两个粒子质心运动(或扭摆运动)在频率简并附近的相对频率,测量了光诱导偶极相互作用强度。实验表明,粒子间光诱导偶极散射对扭摆运动影响很小,未观察到粒子间扭摆运动的相互作用;而质心运动在两束捕获光偏振都垂直于粒子间连线时,产生较强耦合,在两粒子间距为2.91μm时,得到沿捕获光传播方向质心运动在简并点处的耦合强度为1.6 kHz。Optically levitated micro-and nano-particle system is an important platform for the study of many-body physics.However,the previous studies are mainly implemented in the liquid.Recently,due to the obvious advantages,the technique of optical levitation in a vacuum has attracted much attention.In this paper,we experimentally trap two nanoparticles using two individual strongly focused lasers in a vacuum and study the light-induced dipole-dipole interaction of the nanoparticles due to the scattering.In the experiment,a laser beam is directly divided into parts to individually trap two silica nanoparticles.The system is analogous to a Mach Zehnder interferometer(MZI),in which the two nanoparticles are sensitive to the interference intensity of the light fields and therefore can be regarded as reflective mirrors.The constructive or destructive interference of the light fields at the nanoparticles'positions directly determines the strength of the dipole-dipole interaction.This system reduces the noise caused by the phase flicker and improves the trapping stability compared to using a spatial light modulator.The light-induced dipole-dipole interaction is measured by adjusting the relative frequencies of the center-of-mass(Co M)motions(or torsional vibrations)of two nanoparticles near the frequency degeneracy point under different linear polarization conditions.The interaction of the torsional vibrations is not observed in this experiment,which indicates that the dipole scattering almost can't influence this motion mode.While a strong coupling between the Co M motions occurs when the polarizations of the trapping beams are perpendicular to the line between the two particles.The measured coupling strength is 1.6 k Hz.This work is helpful for further studies of the non-reciprocal interaction between two nanoparticles via adjusting the distance between the nanoparticles and the phase difference of trapping beams,the collective motion of light-induced dipole-dipole interaction of nanoparticles,collaborative cooling and manip

关 键 词：光悬浮 光散射 偶极相互作用 

分 类 号：O436.1[机械工程—光学工程]