Towards quantum-enhanced flow sensing methods using nitrogen-vacancy (NV) centers in diamond

Nitrogen-vacancy (NV) centers have garnered significant interest as a versatile nanoscale, quantum-based sensing platform. These vacancies are point defects within a diamond lattice whose electron spin-states are highly sensitive to external perturbations, including temperature, strain, and magnetic and electric fields. NV center-based sensors function by monitoring changes to the spin-states in either an individual or ensemble of NV centers to deduce information about the quantity of interest. Because the spin state can be optically manipulated and read out at normal temperature and pressure, NV center-based diagnostics are becoming an increasingly accessible option for nanoscale sensing across various applications and conditions. Despite the rapid development and proliferation of NV center-based sensing protocols, the fluid mechanics community has yet to fully utilize these emerging capabilities. Here, we discuss the promising outlook for applying this technology to problems in fluid mechanics and the sensing protocols that can be used to access fluid measurements at the nanoscale. We will also present our recent progress toward demonstrating a quantum-enhanced sensing platform for decoherence-based measurements of near-wall flow.