Low-field all-optical detection of superconductivity using NV nanodiamonds
Authors
Omkar Dhungel
Saravanan Sengottuvel
Mariusz Mrozek
Till Lenz
Nir Bar-Gill
Adam M. Wojciechowski
Arne Wickenbrock
Dmitry Budker
Abstract
Nitrogen-vacancy centers in nanodiamond offer a microwave-free, noninvasive platform for probing superconductors via near zero-field cross-relaxation magnetometry. We demonstrate this by depositing nanodiamonds on YBCO thin films to measure critical parameters: transition temperature and penetration field. This method leverages nanodiamond fluorescence modulation as a result of magnetic field variation with 1mT amplitude to observe the Meissner effect and field scans to measure the penetration field. The approach is minimally invasive and can be applied to superconducting samples with rough surfaces, facilitating the study of flux vortices and critical phenomena in complex geometries.
