Magnetoacoustic Resonance to Probe Quadrupole-Strain Coupling in a Diamond Nitrogen-Vacancy Center as a Spin-Triplet System

TL;DR

This paper introduces a theoretical framework for magnetoacoustic resonance in diamond NV centers, enabling measurement of quadrupole-strain couplings and offering an alternative to magnetic spin control.

Contribution

It develops a Floquet theory-based model to analyze phonon-induced transitions in NV centers, revealing how strain couplings can be probed via magnetic field rotation.

Findings

Transition probabilities depend on quadrupole couplings.

Magnetic field rotation controls strain interactions.

Potential for mechanical or ac strain-based spin control.

Abstract

A theory of magnetoacoustic resonance is proposed to measure quadrupole-strain couplings in a spin-triplet state with the $C_{3v}$ point group symmetry, considering the spin-strain interaction in a diamond nitrogen-vacancy (NV) center. Based on the Floquet theory, we demonstrate how the single- and two-phonon transition probabilities depend on the change in the longitudinal and transverse quadrupole couplings, which can be controlled by rotating an applied magnetic field, around the threefold axis. The obtained quadrupole dynamics results are useful for realizing mechanical or ac strain-control of the NV spin as an alternative to the conventional magnetic control by spin resonance.