The performance of NV centers as (nanoscale) magnetic field sensors in quantum sensing or qubits in quantum computing is deduced from several electro-optical properties of the NV centers. In the rating of NV centers, the criteria always have to be evaluated always in view of the application. NV centers for nanoscale NMR wide-field magnetic imaging are usually close to the diamond surface and thus suffer from decoherence originating from this (mostly) uncontrollable interface. Here, especially the stability of its negative charge state as well as coherence time are of interest and form indicators for the NV performance and suitability.
In the application field of wuantum computing, the NV centers are usually deeper in the diamond and already possess long (up to milliseconds) coherence times. Here, the coupling strength and efficacy to other spins (NV centers or 13C nuclear spins) within the diamond matrix are the parameter that determine the performance of NV centera as qubit registers.