Vector detection of AC magnetic fields by Nitrogen-Vacancy centers of single orientation in diamond

TL;DR

This paper introduces a novel method for vector detection of AC magnetic fields using single-orientation NV centers in diamond, enabling measurement of both field strength and direction at the nanoscale.

Contribution

The paper proposes a new technique that allows vector AC magnetic field detection with NV centers of a single orientation, simplifying previous multi-orientation approaches.

Findings

Successful proof of principle experiment conducted

All three electron spin transitions exhibit non-zero dipole moments

Method enables measurement of both magnitude and orientation of AC fields

Abstract

Nitrogen-Vacancy (NV) centers in diamond have useful properties for detecting both AC and DC magnetic fields with high sensitivity at nano-scale resolution. Vector detection of AC magnetic fields can be achieved by using NV centers having three different orientations. Here, we propose a method to achieve this by using NV centers of single orientation. In this method, a static magnetic field is applied perpendicular to the NV axis, leading to strong mixing of the $m_{s}=-1$ and $1$ electron spin states. As a result, all three electron spin transitions of the triplet ground state have non-zero dipole moments, with each transition coupling to a single component of the magnetic field. This can be used to measure both strength and orientation of the applied AC field. To validate the technique, we perform a proof of principle experiment using a subset of ensemble NV centers in diamond, all having the same orientation.