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

Abstract

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.

Microwave-Free Vector Magnetometry with Nitrogen-Vacancy Centers along a Single Axis in Diamond

“…In particular, negatively charged nitrogen-vacancy (NV) centers in single-crystal diamond provide high-sensitivity magnetic sensing and high-resolution imaging [9][10][11] . To date, diamondbased vector magnetometers have been based on using the optically detected magnetic resonance (ODMR) technique with the requirement of applying microwaves (MWs) sequentially or simultaneously [12][13][14] . In these existing implementations, at least three ODMR spectral features must be interrogated to determine the magnetic field vector, and actually four or more are often probed to mitigate systematic errors from strain, electric fields, or temperature variation.…”

Novel Magnetic-Sensing Modalities with Nitrogen-Vacancy Centers in Diamond

“…To date, vector magnetometers based on NV diamond have been realized by interrogating ensembles of NV centers along multiple orientations [45,46] or relying on a hybrid quantum platform involving a NV center probe and a nuclear-spin qubit at particular positions [47]. These techniques, however, are all based on ODMR technique that needs to apply microwaves simultaneously or sequentially [45,46,48].…”

“…To date, vector magnetometers based on NV diamond have been realized by interrogating ensembles of NV centers along multiple orientations [45,46] or relying on a hybrid quantum platform involving a NV center probe and a nuclear-spin qubit at particular positions [47]. These techniques, however, are all based on ODMR technique that needs to apply microwaves simultaneously or sequentially [45,46,48]. The requirement of microwave control brings the possibility of spurious harmonics within the measurement and hinders applications in areas where the application of microwaves is prohibitively invasive and where it is inherently difficult to achieve such control.…”

Demonstration of vector magnetic field sensing by simultaneous control of nitrogen-vacancy centers in diamond using multi-frequency microwave pulses

“…Recently, to overcome this problem of low readout contrast, an approach to vector magnetic field sensing has been proposed in which the four types of NV center with different axes are simultaneously controlled by multi-frequency microwave pulses. [24][25][26] Consequently, all the NV centers irradiated by a green laser contribute to the signal containing information on the magnetic field, in contrast to the conventional approach, in which 75% of the NV centers just induce noise without contributing to the signal. The sensitivity of this method of vector field sensing can, in principle, be four times higher than that of the conventional approach.…”