Spin-Phonon-Photon Strong Coupling in a Piezomechanical Nanocavity

TL;DR

This paper presents a hybrid quantum system integrating a spin, phonon, and photon in a piezomechanical nanocavity, enabling strong coupling and high-fidelity quantum state transfer for advanced quantum information applications.

Contribution

It introduces a novel tripartite hybrid system with strong spin-phonon-photon coupling and high transfer fidelities, advancing quantum hybrid architectures.

Findings

Achieves microwave-acoustic and spin-acoustic coupling rates of ~MHz or greater.

Demonstrates ultra-high cooperativities (~10^3 and ~10^2) for the couplings.

Estimates photon-to-spin quantum state transfer fidelities exceeding 0.97.

Abstract

We introduce a hybrid tripartite quantum system for strong coupling between a semiconductor spin, a mechanical phonon, and a microwave photon. Consisting of a piezoelectric resonator with an integrated diamond strain concentrator, this system achieves microwave-acoustic and spin-acoustic coupling rates $\sim$MHz or greater, allowing for simultaneous ultra-high cooperativities ($\sim 10^3$ and $\sim 10^2$, respectively). From finite-element modeling and master equation simulations, we estimate photon-to-spin quantum state transfer fidelities exceeding 0.97 based on separately demonstrated device parameters. We anticipate that this device will enable hybrid quantum architectures that leverage the advantages of both superconducting circuits and solid-state spins for information processing, memory, and networking.