Enhanced spin-mechanical interaction with levitated micromagnets

TL;DR

This paper presents a protocol to significantly enhance spin-mechanical coupling in a hybrid system of NV spins and levitated micromagnets, enabling high-fidelity quantum states and faster quantum gates.

Contribution

It introduces a method to exponentially increase spin-phonon coupling using electrical modulation of a levitated micromagnet, advancing quantum information processing capabilities.

Findings

Exponential enhancement of spin-phonon coupling strength.

Realization of high-fidelity Schrödinger cat states.

Implementation of fast, high-fidelity geometric phase gates.

Abstract

Spin-mechanical hybrid systems have been widely used in quantum information processing. However, the spin-mechanical interaction is generally weak, making it a critical challenge to enhance the spin-mechanical interaction into the strong coupling or even ultra-strong coupling regime. Here, we propose a protocol that can significantly enhance the spin-mechanical coupling strength with a diamond spin vacancy and a levitated micromagnet. A driving electrical current is used to modulate the mechanical motion of the levitated micromagnet, which induces a two-phonon drive and can exponentially enhance the spin-phonon and phonon-medicated spin-spin coupling strengths. Furthermore, a high fidelity Schrodinger cat state and an unconventional 2-qubit geometric phase gate with high fidelity and faster gate speed can be achieved using this hybrid system. This protocol provides a promising platform for quantum information processing with NV spins coupled to levitated micromagnets.