Master equation-based model for infrared-based magnetometry with nitrogen-vacancy centers in diamond cavities: a path to sub-picotesla sensitivity at sub-millimeter scales

TL;DR

This paper develops a master equation model for IR-based NV center magnetometry in diamond cavities, demonstrating the potential for sub-picotesla sensitivity at sub-millimeter scales, enhancing high-resolution bio-magnetic detection.

Contribution

It introduces a comprehensive master-equation approach that incorporates IR saturation effects, enabling accurate sensitivity predictions and optimization for NV-based magnetometry.

Findings

Potential to reach sub-picotesla sensitivity

Model aligns with experimental results

Optimization shows feasibility at small scales

Abstract

Our study aims to increase the spatial resolution of high-sensitivity magnetometry based on singlet-transition infrared (IR) absorption using nitrogen-vacancy (NV) centers in diamonds in monolithic cavities, with potential applications in bio-magnetic field detection. We develop a master-equation treatment of optically detected magnetic resonance, incorporating IR light saturation effects. This master equation provides the singlet population, which is then utilized to calculate the reflectivity and ultimately derive the magnetic field sensitivity taking into account photon and spin shot noise. We further show that our model is compatible with experiments of IR-based NV center magnetometry. Through optimization in a high-parameter space, we uncover the potential to achieve sensitivities in the order of sub-pico tesla, even for sub-millimeter scales.