Detecting magnetic fields using Nitrogen-Vacancy Centers

TL;DR

This paper demonstrates how nitrogen-vacancy centers can be used to detect magnetic fields by applying quantum state discrimination theory, optimizing measurement strategies, and considering practical limitations like decoherence and photon detection efficiency.

Contribution

It introduces a quantum-based method for magnetic field detection using NV centers, including optimization of measurement timing and strategies considering real-world imperfections.

Findings

Optimized interaction time improves detection accuracy.

Multiple measurements significantly reduce error rates.

Detection efficiency limitations are quantitatively analyzed.

Abstract

We show how nitrogen-vacancy centers can be used to `detect' magnetic fields, that is, to find out whether a magnetic field, about which we may not have complete information, is actually present or not. The solution to this problem comes from quantum state discrimination theory. The effect of decoherence is taken into account to optimize the time over which the nitrogen-vacancy center is allowed to interact with the magnetic field before making a measurement. We also find the optimum measurement that should be performed. We then show how multiple measurements reduce the error in detecting the magnetic field. Finally, a major limitation of the measurement process, namely limited photon detection efficiency, is taken into account. Our proposals should be implementable with current experimental technology.