Rapid vortex flux motion in GdBa2Cu3O7−d nanobridges

Abstract

We report on the vortex dynamics of a GdBa₂Cu₃O_7−δ nanobridge through current-voltage measurements. The study is conducted on a sample with a length of 10 μm, a width of 0.62 μm, and a thickness of 80 nm, which was grown by sputtering and fabricated using a two-step process: first, optical lithography, followed by focused ion beam milling. The results show that the film exhibits a low critical current density but demonstrates high vortex flux motion. From the Larkin–Ovchinnikov instability, we extract velocities exceeding 10 km/s at low temperatures and fields around 0.4 T (with nearly 10 vortices crossing the bridge width) and approximately 3 km/s for fields around 5 T. These results are compared with recent publications reporting high vortex velocities.