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

Cheng Sheng,Xiaodong He,Xiao Li,Kunpeng Wang,Peng Xu,Jiayi Hou,Min Liu,Jin Wang,Mingsheng Zhan,Jun Zhuang

doi:10.1103/physrevresearch.3.023008

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, 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 new sorting algorithm (heuristic cluster algorithm, HCA) which provides near-fewest moves in our tailored atom assembler scheme and experimentally demonstrate a $5\times6$ defect-free atom array with 98.4(7)$\%$ filling fraction for one rearrangement cycle. The feature of HCA that the number of moves $N_{m}\approx N$ ($N$ is the number of defect sites to be filled) makes the filling fraction uniform as the size of atom assembler enlarged. Our method is essential to scale hundreds of assembled atoms for bottom-up quantum computation, quantum simulation and precision measurement.

Highlights

Bottom-up-built single-atom arrays have rapidly developed into a versatile platform for quantum many-body simulation [1,2,3,4], quantum metrology [5,6], and quantum computation [7,8,9,10,11,12]
We propose a sorting algorithm [the heuristic cluster algorithm (HCA)] which provides the near-fewest number of moves Nm ≈ 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
We find that the simulating filling fractions with the HCA and A* searching algorithm (ASA) are approximately constant as the number of filled sites increases, while the heuristic path-finding algorithm (HPFA) shows a rapid decline, which means the HPFA is not appropriate for large-scale atom arrays even with a high transfer efficiency

Summary

INTRODUCTION

Bottom-up-built single-atom arrays have rapidly developed into a versatile platform for quantum many-body simulation [1,2,3,4], quantum metrology [5,6], and quantum computation [7,8,9,10,11,12]. A similar heuristic shortest-move algorithm has been applied to rearrange 111 atoms and the cumulative success rate of a 4 × 4 atom array is less than 20% for one rearrangement cycle mainly limited by a 75% transfer efficiency (might be induced by the short lifetime in the MT) [18]. These sorting algorithms are not optimal for large-scale atom arrays due to a number of redundant moves involved. V we experimentally measure the filling fraction of atom arrays utilizing these algorithms with two different transfer efficiencies and give the results of large-scale atom array simulations

EXPERIMENTAL PREPARATION OF ATOM ASSEMBLERS

ATOM LIFETIMES IN A MOBILE TWEEZER

SORTING-ATOM ALGORITHMS

NUMBER OF MOVES AND FILLING FRACTIONS

Findings

CONCLUSION