Direct Generation of an Array with 78400 Optical Tweezers Using a Single Metasurface

TL;DR

This paper demonstrates the creation of a large optical tweezer array with 78,400 spots using a metasurface, significantly surpassing previous methods and simplifying system design for quantum atom arrays.

Contribution

The authors introduce a metasurface-based technique for directly generating large-scale optical tweezer arrays without additional focusing optics, enabling scalable quantum atom trapping.

Findings

Generated a 280x280 optical tweezer array with 78,400 spots.

Achieved over 90% intensity uniformity across the array.

Paves the way for trapping over 10,000 atoms in quantum computing applications.

Abstract

Scalability remains a major challenge in building practical fault-tolerant quantum computers. Currently, the largest number of qubits achieved across leading quantum platforms ranges from hundreds to thousands. In atom arrays, scalability is primarily constrained by the capacity to generate large numbers of optical tweezers, and conventional techniques using acousto-optic deflectors or spatial light modulators struggle to produce arrays much beyond $\sim 10,000$ tweezers. Moreover, these methods require additional microscope objectives to focus the light into micrometer-sized spots, which further complicates system integration and scalability. Here, we demonstrate the experimental generation of an optical tweezer array containing $280\times 280$ spots using a metasurface, nearly an order of magnitude more than most existing systems. The metasurface leverages a large number of subwavelength phase-control pixels to engineer the wavefront of the incident light, enabling both large-scale tweezer generation and direct focusing into micron-scale spots without the need for a microscope. This result shifts the scalability bottleneck for atom arrays from the tweezer generation hardware to the available laser power. Furthermore, the array shows excellent intensity uniformity exceeding $90\%$, making it suitable for homogeneous single-atom loading and paving the way for trapping arrays of more than $10,000$ atoms in the near future.