Joint quantum sensing of vector magnetic field and temperature with nitrogen-vacancy centers in diamond

Abstract

Quantum diamond sensors of multiple physical quantities, especially magnetic field and temperature, have great application prospects in materials science, biophysics, and engineering. Here, we demonstrate joint quantum sensing of vector magnetic field and temperature based on ensembles of nitrogen-vacancy (NV) centers in the diamond. Combining the intrinsic C3ν symmetry of diamond crystals and multiple-frequency excitation technique, we can directly measure frequency-modulated optically detected magnetic resonance (ODMR) spectra for three different NV orientations and then obtain the Zeeman splittings and the center frequency movement of the electron spin. An artificially generated underlying external magnetic field is used to eliminate degeneracy and facilitate coordinate transformations. The six-channel phase-locked amplification technology enables simultaneous detection of vector magnetic field and temperature with a sensitivity of about 0.87 nT/Hz1/2 and 0.32 mK/Hz1/2; meanwhile, a 23 dB isolation between magnetic and temperature signals is kept. This technology realizes the simultaneous measurement of arbitrary vector magnetic field and temperature, which can be used to study the temperature-varying magnetic phase transition.