Critical Current Control in YBa₂Cu₃O_7-δFilms Using Artificial Pinning Centers

TLDR

High‑temperature superconductors can carry high non‑dissipative currents at low temperatures as long as quantized vortices are pinned, but at 77 K in magnetic fields the currents are insufficient due to weak pinning. The study aims to improve nondissipative currents in YBa₂Cu₃O₇₋δ films by introducing linear defects along the c‑axis. Linear defects were introduced along the c‑axis using a novel nanostructure technology. Marked enhancement of nondissipative currents at 77 K and high fields when the fields were applied close to the c‑axis demonstrated enhanced pinning by the artificial centers.

Abstract

High-temperature superconductors can carry high non dissipative currents at low temperatures as long as quantized vortices are pinned. However, the currents in a magnetic field at liquid nitrogen temperature (77 K) are not sufficiently high for practical use due to the weak pinning. For the improvement of nondissipative currents in YBa 2 Cu 3 O 7-δ films, linear defects that extended to the c -axis of the film were introduced using a novel nanostructure technology. We observed a marked enhancement of the nondissipative currents even at 77 K and high fields when the fields were applied close to the c -axis. This is a clear demonstration of enhanced pinning using artificially incorporated pinning centers.