Accelerating the assembly of defect-free atomic arrays with maximum parallelisms

Defect-free atomic arrays have been demonstrated as a scalable and fully controllable platform for quantum simulations and quantum computations. To push the qubit size limit of this platform further, we design an integrated measurement and feedback system, based on field programmable gate array (FPGA), to quickly assemble a two-dimensional defect-free atomic array using maximum parallelisms. The total time cost of the rearrangement is first reduced by processing atom detection, atomic occupation analysis, rearrangement strategy formulation, and acousto-optic deflectors (AOD)driving signal generation in parallel in time. Then, by simultaneously moving multiple atoms in the same row (column), we save rearrangement time by parallelism in space. To best utilize these parallelisms, we propose a new algorithm named Tetris algorithm to reassemble atoms to arbitrary target array geometry from two-dimensional stochastically loaded atomic arrays. For an L×L target array geometry, the number of moves scales as L, and the total rearrangement time scales at most as L^2. We simulate the performance of our FPGA system experimentally with all components integrated except for the atoms. We present the overall performance for different target geometries and demonstrate a dramatic boost in rearrangement time cost and the potential to scale up defect-free atomic array to 1000 atoms in room-temperature platform and 10000 atoms in a cryogenic environment. We have also conducted performance tests of the FPGA system on atoms without the Tetris algorithm and successfully achieved a defect-free array of several hundred atoms.