Robust phase-controlled gates for scalable atomic quantum processors using optical standing waves

TL;DR

This paper proposes a robust optical standing wave scheme for quantum gates in atomic processors, reducing sensitivity to phase and motion, and enabling scalable, precise quantum operations without tight laser focusing.

Contribution

It introduces a novel standing wave-based method for phase-controlled quantum gates that enhances robustness and scalability in atomic quantum processors.

Findings

Significantly reduces sensitivity to optical phase and atomic motion.

Compatible with robust optimal control and spatial qubit addressing.

Facilitates scalable quantum gates without tight laser focusing.

Abstract

A simple scheme is presented for realizing robust optically controlled quantum gates for scalable atomic quantum processors by driving the qubits with optical standing waves. Atoms localized close to the antinodes of the standing wave can realize phase-controlled quantum operations that are potentially more than an order of magnitude less sensitive to the local optical phase and atomic motion than corresponding travelling wave configurations. The scheme is compatible with robust optimal control techniques and spatial qubit addressing in atomic arrays to realize phase controlled operations without the need for tight focusing and precise positioning of the control lasers. This will be particularly beneficial for quantum gates involving Doppler sensitive optical frequency transitions and provides an all optical route to scaling up atomic quantum processors.