Efficient preparation of two-dimensional defect-free atom arrays with near-fewest sorting-atom moves

Abstract

Sorting atoms stochastically loaded in optical tweezer arrays via an auxiliary mobile tweezer is an efficient approach to preparing intermediate-scale defect-free atom arrays in arbitrary geometries. However, the high filling fraction of atom-by-atom assemblers is impeded by redundant sorting moves with imperfect atom transport, especially for scaling the system size to larger atom numbers. Here we propose a sorting algorithm [the heuristic cluster algorithm (HCA)] which provides the near-fewest number of moves N_{m}≈N (N is the number of defect sites to be filled) and experimentally demonstrate a 5×6 defect-free atom array with 98.4(7)% filling fraction for one rearrangement cycle. Furthermore, we compare the HCA with two other algorithms by simulating results and find that the HCA is well suited for large-scale atom assemblers. Our method is essential to scale hundreds of assembled atoms for bottom-up quantum computation, quantum simulation, and precision measurement.