High-fidelity and robust controlled-Z gates implemented with Rydberg atoms via echoing rapid adiabatic passage

TL;DR

This paper introduces a robust, high-fidelity controlled-Z gate scheme using rapid adiabatic passage with Rydberg atoms, achieving fidelities over 0.9995, suitable for scalable quantum computing.

Contribution

It presents a novel RAP-based method for implementing high-fidelity CZ and multi-qubit gates with robustness against experimental imperfections.

Findings

Fidelity over 0.9995 for CZ gate

Fidelity exceeding 0.999 for CCZ gate

Four-qubit CCCZ gate with fidelity over 0.996

Abstract

High-fidelity and robust quantum gates are essential for quantum information processing, where neutral Rydberg atoms trapped in optical tweezer arrays serving as a versatile platform for the implementation. We propose a rapid adiabatic passage (RAP) scheme for achieving a high-fidelity controlled-Z (CZ) gate on a neutral atom Rydberg platform. Utilizing only global laser dressing, our scheme involves echoing two identical RAP pulses within the Rydberg blockade regime to realize a CZ gate and can be readily extended to a C$^k$Z gate with additional qubits. We predict a CZ gate with fidelity over 0.9995 using akali-atom parameters, and a CCZ gate with fidelity exceeding 0.999. Moreover, the direct utilization of echoing RAP pulses enables the implementation of a four-bit CCCZ gate at fidelity over 0.996 without further optimization. The proposed scheme, remarkably robust to variations in driving fields and realistic decoherence effects, holds promise for future quantum information processing applications.