Optimization temperature sensitivity using the optically detected magnetic resonance spectrum of a nitrogen-vacancy center ensemble

TL;DR

This paper uses ODMR spectra of NV centers to estimate noise parameters, predict temperature sensitivity, and demonstrate significantly improved sensitivity in nanoscale temperature sensing.

Contribution

It introduces a method to estimate noise parameters from ODMR spectra and predicts enhanced temperature sensitivity based on NV center concentration.

Findings

Optimal sensitivity of 0.76 mK/Hz^(1/2) predicted at high NV concentration

Sensitivity surpasses previous reports, showing potential for nanoscale thermometry

Noise parameters depend strongly on NV spin concentration

Abstract

Temperature sensing with nitrogen vacancy (NV) centers using quantum techniques is very promising and further development is expected. Recently, the optically detected magnetic resonance (ODMR) spectrum of a high-density ensemble of the NV centers was reproduced with noise parameters [inhomogeneous magnetic field, inhomogeneous strain (electric field) distribution, and homogeneous broadening] of the NV center ensemble. In this study, we use ODMR to estimate the noise parameters of the NV centers in several diamonds. These parameters strongly depend on the spin concentration. This knowledge is then applied to theoretically predict the temperature sensitivity. Using the diffraction-limited volume of 0.1 micron^3, which is the typical limit in confocal microscopy, the optimal sensitivity is estimated to be around 0.76 mK/Hz^(1/2) with an NV center concentration of 5.0e10^17/cm^3. This sensitivity is much higher than previously reported sensitivities, demonstrating the excellent potential of temperature sensing with NV centers.