Hybrid quantum device based on NV centers in diamond nanomechanical resonators plus superconducting waveguide cavities

TL;DR

This paper proposes a hybrid quantum device integrating NV centers in diamond with nanomechanical resonators and superconducting cavities, enabling strong coupling and coherent information transfer for quantum information processing.

Contribution

It introduces a novel hybrid system combining spin, mechanical, and photonic components with tunable interactions for quantum technology applications.

Findings

Strong coupling between diamond resonator motion and cavity photons.

Effective spin-photon coupling via mechanical dark polaritons.

Tunable interactions enabled by external fields.

Abstract

We propose and analyze a hybrid device by integrating a microscale diamond beam with a single built-in nitrogen-vacancy (NV) center spin to a superconducting coplanar waveguide (CPW) cavity. We find that under an ac electric field the quantized motion of the diamond beam can strongly couple to the single cavity photons via dielectric interaction. Together with the strong spin-motion interaction via a large magnetic field gradient, it provides a hybrid quantum device where the dia- mond resonator can strongly couple both to the single microwave cavity photons and to the single NV center spin. This enables coherent information transfer and effective coupling between the NV spin and the CPW cavity via mechanically dark polaritons. This hybrid spin-electromechanical de- vice, with tunable couplings by external fields, offers a realistic platform for implementing quantum information with single NV spins, diamond mechanical resonators, and single microwave photons.