Scanning quantum vortex microscopy reveals thickness-dependent pinning nano-network in superconducting Nb-films

• Main Authors: Hovhannisyan, Razmik A, Grebenchuk, Sergey Yu, Shishkin, Andrey G, Grebenko, Artem, Kupchinskaya, Nadezhda E, Dobrovolskaya, Ekaterina S, Skryabina, Olga V, Aladyshkin, Alexey Yu, Golovchanskiy, Igor A, Samokhvalov, Alexey V, Melnikov, Alexander S, Roditchev, Dimitri, Stolyarov, Vasily S
• Format: Journal Article
• Language: English
• Published: 29-03-2024
• Subjects: Physics - Materials Science; Physics - Mesoscale and Nanoscale Physics; Physics - Superconductivity
• DOI: 10.48550/arxiv.2403.20125

The presence of quantum vortices determines the electromagnetic response of
superconducting materials and devices. Controlling the vortex motion, their
pinning on intrinsic and artificial defects is therefore essential for
superconducting electronics. Here we take advantage of the attractive force
between a magnetic cantilever of the Magnetic Force Microscope and a single
quantum vortex to spatially map the pinning force inside 50-240 nm thick
magnetron-sputtered Nb-films, commonly used in advanced superconducting
electronics. The revealed pinning nano-network is related to the
thickness-dependent granular structure of the films as well as to the
characteristic microscopic scales of superconductivity. Our approach is
general, and can be directly applied to other type II granular superconducting
materials and nanodevices.