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.

基于氮化硅的微腔是一种应用广泛的集成光学器件，不仅可以输出用于精密测距和光钟的光频梳，而且能够作为高效的片上量子光源。微腔中光频梳的稳定性是实际应用的重要条件。在理论和实验上研究了氮化硅微腔中光频梳的演化及热自稳定性。在微腔非线性过程和热动力学的基础上，分析了在不同功率和失谐的连续光泵浦下微腔中光频梳的梳态演化和热自稳定性。结果表明，可以通过精确控制微腔的泵浦功率和失谐量调节“图灵环”态的输出，同时微腔系统可通过功率和波长扰动导致的共振漂移补偿噪声的影响，实现稳定运转。该研究为基于微腔量子光源的实验提供了必要基础。

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.

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 π-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.