Polarization‐Dependent Calibration of Nitrogen‐Vacancy Axes for Precise Three‐Dimensional Magnetic Field Vector Determination

Abstract Accurate knowledge of magnetic field orientation is critical for spin‐based quantum magnetometry and its applications in spin‐based quantum computation. Nitrogen‐vacancy (NV) center‐based magnetometers enable direct magnetic field direction measurement through the NV axis, necessitating precise crystal axis direction determination in vector magnetic field measurements of ensemble NV centers in diamond. In this paper, a method is presented that utilizes the optical polarization dependence of NV centers to install a protocol for detecting the orientation of the NV axis. This approach explicitly demonstrates the relationship between the polarization angle and the azimuthal angle of the NV axis, while remaining fully compatible with existing systems. It provides a straightforward and precise NV axis calibration technique for vector magnetic field measurements using NV ensembles, significantly improving the accuracy of magnetic field direction determination.