Probing Vortex Dynamics in Confined Geometries of Van der Waals Superconductors Using Scanning Nitrogen-Vacancy Center Magnetometry

Understanding vortex dynamics in van der Waals superconducting structures is crucial for optimizing the design of nanoscale devices. To probe phenomena at these scales, nitrogen-vacancy (NV) centers inside scanning probes can offer high spatial resolution and sensitivity over a wide range of temperatures from cryogenic to room temperature. We employed a scanning NV probe to visualize vortices in micron-sized geometries by measuring the magnetic stray fields generated by circulating supercurrents. The high sensitivity and spatial resolution of the scanning NV probe enable the two-dimensional current distribution to be uniquely reconstructed from the magnetic stray fields. This visualization illuminates the shape and arrangement of vortices as a function of the applied magnetic field. These measurements provide insights into vortex-vortex interactions in confined environments, as well as vortex-edge effects. Van der Waals superconductors open exciting opportunities for exploring vortex behavior, particularly in small, confined geometries and thin layers.