Fast entangling gates for Rydberg atoms via resonant dipole-dipole interaction

TL;DR

This paper presents a fast, robust entangling gate scheme for neutral-atom quantum computers using resonant dipole-dipole interactions driven by microwaves, improving speed and stability over existing methods.

Contribution

Introduces a microwave-driven entangling gate scheme utilizing four atomic levels and resonant dipole-dipole interactions, eliminating the need for optical phase modulation.

Findings

Gates are faster and less sensitive to Rydberg decay than van der Waals-based gates.

Protocol is robust against interatomic distance fluctuations.

Applicable to realistic rubidium and cesium atom setups.

Abstract

The advent of digital neutral-atom quantum computers relies on the development of fast and robust protocols for high-fidelity quantum operations. In this work, we introduce a novel scheme for entangling gates using four atomic levels per atom: a ground-state qubit and two Rydberg states. A laser field couples the qubit to one of the two Rydberg states, while a microwave field drives transitions between the two Rydberg states, enabling a resonant dipole-dipole interaction between different atoms. We show that controlled-Z gates can be realized in this scheme without requiring optical phase modulation and relying solely on a microwave field with time-dependent phase and amplitude. We demonstrate that such gates are faster and less sensitive to Rydberg decay than state-of-the-art Rydberg gates based on van der Waals interactions. Moreover, we systematically stabilize our protocol against interatomic distance fluctuations and analyze its performance in realistic setups with rubidium or cesium atoms. Our results open up new avenues to the use of microwave-driven dipolar interactions for quantum computation with neutral atoms.