Two-qubit gate in neutral atoms using transitionless quantum driving

TL;DR

This paper presents a fast, high-fidelity controlled-Z gate for neutral atoms using transitionless quantum driving, achieving a fidelity of 0.9985 in 0.12 microseconds, surpassing current experimental methods.

Contribution

It introduces a novel transitionless quantum driving approach for Rydberg-based CZ gates that improves speed and fidelity over existing techniques.

Findings

Achieved a CZ gate fidelity of 0.9985

Operation time of 0.12 microseconds

Outperforms adiabatic and current experimental gates

Abstract

A neutral-atom system serves as a promising platform for realizing gate-based quantum computing because of its capability to trap and control several atomic qubits in different geometries and the ability to perform strong, long-range interactions between qubits; however, the two-qubit entangling gate fidelity lags behind competing platforms such as superconducting systems and trapped ions. The aim of our work is to design a fast, robust, high-fidelity controlled-Z (CZ) gate, based on the Rydberg-blockade mechanism, for neutral atoms. We propose a gate procedure that relies on simultaneous and transitionless quantum driving of a pair of atoms using broadband lasers. By simulating a system of two interacting Caesium atoms, including spontaneous emission from excited levels and parameter fluctuations, we yield a Rydberg-blockade CZ gate with fidelity 0.9985 over an operation time of $0.12~\mu$s. Our gate procedure delivers CZ gates that are superior than the state-of-the-art experimental CZ gate and the simulated CZ gates based on adiabatic driving of atoms. Our results show that our gate procedure carries significant potential for achieving scalable quantum computing using neutral atoms.