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 ms=−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.
@article{arxiv.2308.09325,
title = {Vector detection of AC magnetic fields by Nitrogen-Vacancy centers of single orientation in diamond},
author = {Pooja Lamba and Akshat Rana and Sougata Halder and Siddharth Dhomkar and Dieter Suter and Rama K. Kamineni},
journal= {arXiv preprint arXiv:2308.09325},
year = {2026}
}