The defect-free neutral atom array has emerged as an ideal platform to investigate complex many-body physics of interacting quantum particles, offering the opportunities for quantum simulation and quantum-enhanced metrology. To fast build a large-scale quantum system, we design a sorting-atom algorithm with maximum parallelisms. Compared with previous protocols, our method saves the rearrangement time by sorting row-by-row and is also universal to arbitrary periodic patterns with no need to change the hardware. We present the generation of a defect-free square and other periodic geometries and demonstrate the potential to scale up a defect-free array to 2500 atoms with only about 180 steps of rearrangement.optical tweezer defect-free atomic array
Chinese Optics Letters
2023, 21(11): 110010
2023, 60(11): 1106029
Spin-squeezed state is a many-body entangled state of great interest for precision measurements. Although the absolute sensitivity at the standard quantum limit is better for a larger atom number, the greater dominance of classical noises over atom projection noise makes it harder to achieve spin squeezing. Here, we show both theoretically and experimentally that adiabatic pulse control of the pump field in state preparation is indispensable to sufficient noise suppression, which is the prerequisite for spin squeezing. This technique is generally applicable to spin-squeezing experiments involving a large ensemble and is thus of significance for quantum metrology applications.
2021, 9(11): 11002296
Harnessing the dynamics of complex quantum systems is an area of much interest and a quantum simulator has emerged as a promising platform to probe exotic topological phases. Since the flexibility offered by various controllable quantum systems has helped gain insight into the quantum simulation of such complicated problems, an analog quantum simulator has recently shown its feasibility to tackle the problems of exploring topological phases. However, digital quantum simulation and the detection of topological phases still remain elusive. Here, we develop and experimentally realize the digital quantum simulation of topological phases with a solid-state quantum simulator at room temperature. Distinct from previous works dealing with static topological phases, the topological phases emulated here are Floquet topological phases. Furthermore, we also illustrate the procedure of digitally simulating a quantum quench and observing the nonequilibrium dynamics of Floquet topological phases. Using a quantum quench, the 0- and -energy topological invariants are unambiguously detected through measuring time-averaged spin polarizations. We believe our experiment opens up a new avenue to digitally simulate and detect Floquet topological phases with fast-developed programmable quantum simulators.
2021, 9(1): 01000081
基于普通单模光纤(SMF)和空芯光子晶体光纤(PCF),设计了一种新型的超短光脉冲压缩系统。采用近似解光脉冲传输非线性薛定谔方程和数值模拟方法,研究了二阶色散和三阶色散在超短光脉冲压缩系统和传输系统中的频率啁啾补偿,模拟了自相位调制(SPM)效应对色散补偿的影响并分析了其作用机理。研究发现,在超短光脉冲压缩系统中,当SPM效应增大时,补偿超短光脉冲频率啁啾所需的二阶色散将经历一个非线性过程,补偿其频率啁啾所需的三阶色散将经历一个与之对应的相反过程。非线性光学 非线性效应 高阶色散 色散补偿 光脉冲压缩 nonlinear optics nonlinear effect high-order dispersion dispersion compensation optical pulse compression
从理论上定义了基于高斯脉冲成分分析的激光脉冲时域响应的偏离度参数，并且通过实验验证了该定义的有效性。利用高速光电探测系统测量入射和出射的微秒量级激光脉冲的实际能量分布，在3%的容差范围内对能量分布进行高斯脉冲分量拟合，通过对比各独立高斯成分的归一化强度经系统后的理想值与真实值，计算得到偏离度。在该定义下，通过分析各高斯分量的权重演化以及新分量的成因，不仅可以研究光场与系统相互作用的物理机制，而且为系统的优化设计提供帮助。激光脉冲 偏离度 高斯分量 时域 laser pulse deviation Gaussian components time domain