ac Sensing Using Nitrogen-Vacancy Centers in a Diamond Anvil Cell up to 6 GPa

Nitrogen-vacancy color centers in diamond have attracted broad attention as quantum sensors for both static and dynamic magnetic, electrical, strain, and thermal fields and are particularly attractive for quantum sensing under pressure in diamond anvil cells. Optically based nuclear magnetic resonance may be possible at pressures greater than a few gigapascals and offers an attractive alternative to conventional Faraday-induction-based detection. Here, we present ac sensing results and demonstrate synchronized readout up to 6 GPa but find that the sensitivity is reduced due to inhomogeneities of the microwave field and pressure within the sample space. These experiments enable the possibility of all-optical high resolution magnetic resonance of nanoliter sample volumes at high pressures.