Superconductors using Ensemble Nitrogen Vacancy (NV) Centers in Diamond*

Nitrogen-Vacancy (NV) centers are excellent quantum sensors due to their long spin-coherence time and ultrahigh magnetic field sensitivity. An ensemble of NVs can be used for vector magnetometry of high-T_c superconductors to investigate several processes of interest with nanometer resolution over a wide field. We study the feasibility of measuring vortex dynamics, which plays a pivotal role in understanding the mechanisms underlying superconductivity. In this work, we make a fully functional simulation of a thin-film type-II superconductor with properties similar to materials like BSCCO or YBCO and theoretically demonstrate a scheme for mapping vortices in real time. Utilizing the capabilities of the NV center as a high-speed imaging sensor, we can probe the dynamics of vortex pinning and nucleation. Effects of impurities, thermal fluctuations, varying thickness and other defects can be examined through NVs with nanometer resolution as shown in our simulations as well.