Numerically optimized amplitude-robust controlled-Z gate for ultracold neutral atoms with individual addressing capability

TL;DR

This paper presents a numerically optimized, amplitude-robust controlled-Z gate for ultracold neutral atoms that enhances robustness to Rabi frequency variations and supports individual atom addressing.

Contribution

The authors introduce a new gate scheme with analytically defined phase profiles that significantly improves robustness and applicability for individual addressing in Rydberg atom systems.

Findings

Increased robustness to Rabi frequency variations by nearly an order of magnitude.

Effective for both single-photon and two-photon Rydberg excitation schemes.

Reduces effects of thermal motion and beam pointing instability on gate fidelity.

Abstract

We numerically optimized a scheme for a neutral atom Rydberg blockade symmetric controlled-Z (CZ) gate to increase its robustness to variations in the Rabi frequency. This gate scheme uses analytically defined phase profiles of the laser pulse and demonstrates increased robustness to variations in the Rabi frequency almost by an order of magnitude compared to previous proposals. We demonstrate the applicability of our gate protocol to individual addressing in Rydberg excitation, taking into account the asymmetry of Rabi frequencies for two atoms that are individually excited by tightly focused laser beams. This allows for reducing the effects of residual thermal motion of trapped atoms and beam pointing instability on gate fidelities. We investigated the performance of our gate protocol for single-photon and two-photon Rydberg excitation schemes and showed its advantages for individual addressing at finite temperatures of trapped atoms.