Temperature dependence of the nitrogen-vacancy magnetic resonance in diamond

TL;DR

This study investigates how the magnetic resonance spectra of nitrogen-vacancy centers in diamond change with temperature between 280-330 K, revealing significant variations in key parameters that impact magnetometer performance.

Contribution

The paper provides the first detailed measurement of temperature dependence of ZFS parameters in NV- ensembles across different sample conditions, highlighting implications for diamond magnetometry.

Findings

The axial zero-field splitting parameter D decreases with temperature at -74.2 kHz/K.

The transverse ZFS parameter E is non-zero and also varies with temperature.

Temperature dependence of ZFS parameters may limit the bandwidth and sensitivity of room-temperature diamond magnetometers.

Abstract

The temperature dependence of the magnetic resonance spectra of nitrogen-vacancy (NV-) ensembles in the range of 280-330 K was studied. Four samples prepared under different conditions were studied with NV- concentrations ranging from 10 ppb to 15 ppm. For all of these samples, the axial zero-field splitting (ZFS) parameter, D, was found to vary significantly with temperature, T, as dD/dT = -74.2(7) kHz/K. The transverse ZFS parameter, E, was non-zero (between 4 and 11 MHz) in all samples, and exhibited a temperature dependence of dE/(EdT) = -1.4(3) x 10^(-4) K^(-1). The results might be accounted for by considering local thermal expansion. The observation of the temperature dependence of the ZFS parameters presents a significant challenge for room-temperature diamond magnetometers and may ultimately limit their bandwidth and sensitivity.