Symmetric Rydberg controlled-Z gates with adiabatic pulses

TL;DR

This paper investigates symmetric Rydberg controlled-Z gates using adiabatic pulses, demonstrating high-fidelity Bell state generation with robustness to motion and environmental effects, advancing quantum gate implementation with neutral atoms.

Contribution

It introduces optimized adiabatic pulse protocols for symmetric Rydberg CZ gates that achieve near-perfect fidelity without individual addressing.

Findings

Bell states with fidelity >0.999 predicted with smooth pulses

Optimized two-photon excitation yields Bell states with fidelity 0.997

Gate protocols are robust against Doppler shifts and do not require individual addressing

Abstract

We analyze neutral atom Rydberg $C_Z$ gates based on adiabatic pulses applied symmetrically to both atoms. Analysis with smooth pulse shapes and Cs atom parameters predicts the gates can create Bell states with fidelity ${\mathcal F}>0.999$ using adiabatic rapid passage (ARP) pulses. With globally optimized adiabatic pulse shapes, in a two-photon excitation process, we generate Bell states with fidelity ${\mathcal F}=0.997$. The analysis fully accounts for spontaneous emission from intermediate and Rydberg states, including the Rydberg lifetime in a room temperature environment, but does not include errors arising from laser noise. The gate protocols do not require individual addressing and are shown to be robust against Doppler shifts due to atomic motion.