基于微尺度光学偶极阱的一维单原子阵列的实验制备

Experimental realization of one-dimensional single-atom array based on microscale optical dipole traps

光学偶极阱俘获的中性原子阵列是多体物理、量子计算、量子模拟等领域的重要实验平台.本文详细介绍了制备包含40个铯原子的一维均匀单原子阵列的实验过程,包括偶极阱阵列的产生装置、原子阵列荧光成像以及偶极阱阵列均匀性优化.偶极阱阵列的非均匀性主要是由声光偏转器(AOD)衍射效率的非线性和多频率射频信号在功率放大过程中的互调效应引起.测量偶极阱光强和受俘获原子光频移的起伏并反馈优化施加于AOD多频率射频信号的相位和振幅,将偶极阱阵列的强度均匀性优化为2%.另外,实验测量了偶极阱阵列内原子的振荡频率、装载率和寿命的均匀性.结果显示,振荡频率均匀性为2%;单原子平均装载率为58%,阱中原子的光谱一致性为3%;单原子暗阱平均寿命约为6(1) s,不同原子寿命的起伏为8%.

Neutral atom array serves as a crucial experimental platform for studying many-body physics,quantum computing,and quantum simulation.In this work,we describe in detail the experimental process of preparing a one-dimensional homogeneous single atom array containing 40 Cs atoms,including the dipole trap array generation device,atomic array fluorescence imaging,and the uniformity optimization of the dipole trap array.The beam waist of the dipole trap is about 1.8μm,and the spatial resolution of the imaging system is higher than 1.55μm.The non-uniformity of dipole trap array is mainly caused by the intermodulation effect of multi-tone signal during amplification.The uniformity of the dipole trap array is optimized to 2%(Fig.(a))by measuring the fluctuations of the dipole trap intensity and the light shift of trapped atom,and providing feedback to adjust the phase and amplitude applied to the multi-tone RF signal on acousto-optic deflectors.Furthermore,the uniformity of oscillation frequency,loading rate,and lifetime for trapped atom in the dipole trap array are measured.These results show that oscillation frequency has a uniformity within 2%(Fig.(b));mean loading rate is around 58%with a uniformity within 3%;and mean lifetime of single atom in dark trap is around 6(1)s with a uniformity within 8%.