Vector magnetometer based on synchronous manipulation of nitrogen-vacancy centers in all crystal directions

Negatively charged nitrogen vacancy (NV^-) centers in diamond have been extensively studied as high-sensitivity magnetometers, showcasing a wide range of applications. This study experimentally demonstrates a vector magnetometry scheme based on synchronous manipulation of NV^- center ensembles in all crystal directions using double frequency microwaves (MWs) and multi-coupled-strip-lines (mCSL) waveguide. The application of the mCSL waveguide ensures a high degree of synchrony (99%) for manipulating NV^- centers in multiple orientations in a large volume. Manipulation with double frequency MWs makes NV^- centers of all four crystal directions involved, and additionally leads to an enhancement of the manipulation field. In this work, by monitoring the changes in the slope of the resonance line consisting of multi-axes NV^- centers, measurement of the direction of the external field vector was demonstrated with a sensitivity of . Based on the scheme, the fluorescence signal contrast was improved by four times higher and the sensitivity to the magnetic field strength was improved by two times. The method provides a more practical way of achieving vector sensors based on NV^- center ensembles in diamond.