Nuclear Quantum-Assisted Magnetometer

TL;DR

This paper presents a nitrogen-vacancy center-based scanning magnetometer that uses quantum-assisted readout to significantly improve signal-to-noise ratio, enhancing magnetic sensing capabilities for biological and material sciences.

Contribution

Introduction of a quantum-assisted readout scheme for NV center magnetometry that boosts sensitivity and spatial resolution over standard methods.

Findings

Near tenfold enhancement in signal-to-noise ratio.

Demonstrated improved $T_1$ relaxation time measurement.

Advances in photon collection efficiency contributed to performance.

Abstract

Magnetic sensing and imaging instruments are important tools in biological and material sciences. There is an increasing demand for attaining higher sensitivity and spatial resolution, with implementations using a single qubit offering potential improvements in both directions. In this article we describe a scanning magnetometer based on the nitrogen-vacancy center in diamond as the sensor. By means of a quantum-assisted readout scheme together with advances in photon collection efficiency, our device exhibits an enhancement in signal to noise ratio of close to an order of magnitude compared to the standard fluorescence readout of the nitrogen-vacancy center. This is demonstrated by comparing non-assisted and assisted methods in a $T_1$ relaxation time measurement.