Spin properties of NV centers in high-pressure, high-temperature grown diamond

Abstract

The sensitivity of magnetic and electric field sensors based on nitrogen-vacancy (NV) center in diamond strongly depends on the available concentration of NV and their coherence properties. Achieving high coherence times simultaneously with high concentration is a challenging experimental task. Here, we demonstrate that by using a temperature gradient method of high-pressure, high-temperature growing technique, one can achieve nearly maximally possible dephasing T 2 * times, limited only by carbon nuclear spins at low nitrogen concentrations or nitrogen electron spin at high nitrogen concentrations. Hahn-echo T 2 coherence times were also investigated and found to demonstrate reasonable values. Thus, the high-pressure, high-temperature technique is a strong contender to the popular chemical vapor deposition method in the development of high-sensitivity, diamond-based sensors.

NV– diamond laser

“…Monocrystalline samples of IIa-type diamond with NV color centers created by means of high pressure and high temperature synthesis (HPHT) are currently available on the market [28][29][30] . Spectroscopic characteristics of NV − centers in diamond were investigated in 26 ; however, stimulated emission or lasing at NV centers in diamond have not been achieved in that work.…”

Investigation of High‐Density Nitrogen Vacancy Center Ensembles Created in Electron‐Irradiated and Vacuum‐Annealed Delta‐Doped Layers

“…A home‐built scanning microscope using a long focal length objective (Olympus Plan Achromat 10× NA 0.25) with the external microwave part of the setup (see details in Rubinas et al [ 31 ] ) was used to manipulate the NV center spin and measure coherence times. Two permanent magnets were used to adjust the magnetic field, one aligned along the optical axis and the other perpendicular to it.…”

“…Once the single orientation transition was isolated, coherent manipulation of the electron spin was performed. First, Rabi oscillations of spin under excitation by a microwave field were observed to obtain a π pulse duration required to implement Ramsey and Hahn echo spectroscopy (see details in Rubinas et al [ 31 ] ).…”

“…Then, the Hahn echo sequence [ 31 ] was used to define the coherence time T 2 for the NV center electron spin. For a proper investigation of the NV center coherence time, a 110 G permanent magnetic field was applied, required for observing revivals in the Hahn echo signal corresponding to interaction of C 13 atoms with NV centers.…”

Laser threshold magnetometry using green-light absorption by diamond nitrogen vacancies in an external cavity laser

“…We therefore consider values in the experimental literature as a guide. Figure 2 shows a plot of T * 2 versus NV − density N NV for a range of diamonds from the literature [16,38,[43][44][45][46][47]. Typical NV − densities range from 10 −4 ppm up to tens of ppm [48].…”