Optically detected magnetic resonance of nitrogen-vacancy centers in microdiamonds inside nanopolycrystalline diamond anvil cell

Abstract

We demonstrated optically detected magnetic resonance (ODMR) of nitrogen-vacancy (NV) centers in microdiamonds inside a diamond anvil cell pressurized with nanopolycrystalline diamond (NPD) anvils. NPD exhibits high optical transparency, superior hardness, and low thermal conductivity, making it suitable for optical and spectroscopic measurements under high-pressure and high-temperature conditions. We observed the ODMR signal from an ensemble of NV centers under conditions where NV centers in microdiamonds served as markers for pressures exceeding 30 GPa, with a culet diameter of 600 $μ$m. We also performed ODMR measurements on multiple microdiamonds sealed inside a sample chamber and found that the resonance frequency varied with the pressure distribution. The combination of NPD and microdiamonds containing NV centers is auspicious for pressure and magnetic sensing under concurrent high-pressure and high-temperature conditions.

Figures (5)

• Figure 1: (a) Energy diagram of NV center. A magnetic field $B$ along the NV center splits the $\ket{{\pm{1}}}$ states via Zeeman interaction. An isotoropic pressure $P$ and temperature $T$ shifts the ZFS in the opposite directions. Anisotropic pressure splits the $\ket{{\pm{1}}}$ states. (b) Setup of the nanopolycrystalline diamond anvil cell. Light-blue region indicates the pressure-transmitting medium (glycerin) in the sample chamber formed by a rhenium gasket. The initial gasket thickness was 250 $\mu$m and was pre-indented to 50–60 $\mu$m; the sample-chamber hole diameter was 200–300 $\mu$m. The microdiamonds are placed on the culet surface. (c) Setup for the optical measurements. DM and LP denote dichroic mirror and long pass filter, respectively. (d) Normalized photoluminescence (PL) intensity of microdiamond (MD) on nanopolycrystalline diamond (NPD) and NPD itself, compared with Type IIa single-crystalline diamond. The vertical axis is normalized to the PL intensity of the MD on the corresponding anvil: for the NPD data, to the PL intensity of the MD on NPD; and for the SCD data, to the PL intensity of the MD on SCD.
• Figure 2: CW ODMR spectra of the MD labeled NV1 under high pressure with (a) increasing pressure process and (b) decreasing pressure process. The vertical axes are normalized by the PL intensity of the ambient pressure, labeled as P0. The black lines indicate fitting curves. The black arrows in (b) indicate the measurement order.
• Figure 3: Pressure estimated from ODMR at each measurement sequence. Pressures are estimated using $P_{\rm ODMR}=(D-D_0)/\beta$ GPa, where $D_0=2.87\times10^9$ Hz, $\beta = 14.58\times10^6$ GPa/Hz, and $D$ denotes resonance frequency dohertyElectronicPropertiesMetrology2014. The error bar represents a 95$\%$ confidence interval of the fitted value of $D$.
• Figure 4: (a) CW ODMR spectra on three MDs with NV center, termed as NV1, NV2, and NV3, respectively. The results of P6 are presented in this section. NV1 is the same as that used in Figs \ref{['f2']} and \ref{['f3']}. These spectra have offsets of $-0.05$ for NV2 and $-0.1$ for NV3, respectively. The inset shows the position of each MD in the sample space. (b) CW ODMR spectra on NV1 at pressure sequence of P8 with no bias field and finite bias field. The spectrum obtained under finite bias field has offsets of $-0.08$.
• Figure 5: (a) Fluorescence image of the MDs captured by the EMCCD camera. (b) CW ODMR spectra under high pressure. The spectra are offset by $0.02$ each for clarity.