Fast and Coherent Transfer of Atomic Qubits in Optical Tweezers using Fiber Array Architecture

TL;DR

This paper demonstrates ultrafast, low-heating coherent transfer of neutral-atom qubits in an optical fiber array architecture, significantly advancing quantum computing scalability and fidelity.

Contribution

It introduces a fiber array architecture enabling fast, coherent qubit transfer with ultralow motional heating, improving speed and fidelity over previous methods.

Findings

Achieved 10 μs in situ transfer with negligible atom loss and high fidelity.

Demonstrated 120 μs inter-site transfer with minimal heating and high fidelity.

Established a model linking array inhomogeneity to transfer heating rate.

Abstract

Programmable neutral-atom arrays offer a promising route toward scalable quantum computing, where coherent qubit transfer enables non-local connectivity and reduces resource overhead. However, transfer speed and motional heating remain key bottlenecks for fast and deep quantum circuits. Here, we employ a fiber array neutral-atom quantum computing architecture with site-resolved control of trap depths to realize smooth amplitude exchange between static and moving traps, thereby enabling fast and coherent qubit transfer with ultralow motional heating. With a 10 $\mu$s in situ transfer between static and moving traps, we obtain a per-cycle heating rate of 0.156(9) $\mu$K, sustain over 500 cycles with negligible atom loss, and achieve a quantum state fidelity of 0.99992(5) per cycle. For inter-site transfer between two separated static traps, the operation takes 120 $\mu$s with 0.783(17) $\mu$K heating per transfer, and remains negligible atom loss for up to 100 repeated cycles with a fidelity of 0.9998(1) per transfer. Furthermore, through experimental studies of parallel transfer, we establish a model that elucidates the relationship between array inhomogeneity and the transfer heating rate. This fast, low-heating coherent transfer capability provides a practical route for improving both speed and fidelity in atom-shuttling based quantum computing.