High-tolerance antiblockade SWAP gates using optimal pulse drivings

TL;DR

This paper presents a robust Rydberg antiblockade SWAP gate protocol that uses optimized pulse shapes and modified conditions to significantly reduce position errors and maintain high fidelity under realistic experimental noise.

Contribution

It introduces a high-tolerance antiblockade scheme with optimized pulses that reduces error sensitivity and improves gate fidelity in Rydberg atom systems.

Findings

Reduced double Rydberg state time by over 70%

Gate fidelity maintained above 0.91 under experimental imperfections

Enhanced robustness against Doppler dephasing and laser fluctuations

Abstract

Position error is treated as the leading obstacle that prevents Rydberg antiblockade gates from being experimentally realizable, because of the inevitable fluctuations in the relative motion between two atoms invalidating the antiblockade condition. In this work we report progress towards a high-tolerance antiblockade-based Rydberg SWAP gate enabled by the use of {\it modified} antiblockade condition combined with carefully-optimized laser pulses. Depending on the optimization of diverse pulse shapes our protocol shows that the amount of time-spent in the double Rydberg state can be shortened by more than $70\%$ with respect to the case using {\it perfect} antiblockade condition, which significantly reduces this position error. Moreover, we benchmark the robustness of the gate via taking account of the technical noises, such as the Doppler dephasing due to atomic thermal motion, the fluctuations in laser intensity and laser phase and the intensity inhomogeneity. As compared to other existing antiblockade-gate schemes the predicted gate fidelity is able to maintain at above 0.91 after a very conservative estimation of various experimental imperfections, especially considered for realistic interaction deviation of $\delta V/V\approx 5.92\%$ at $T\sim20$ $\mu$K. Our work paves the way to the experimental demonstration of Rydberg antiblockade gates in the near future.