Deformation and Depinning of Superconducting Vortices from Artificial Defects: A Ginzburg-Landau Study

TL;DR

This study uses Ginzburg-Landau theory to analyze how superconducting vortices interact with artificial defects, revealing a core string formation that influences vortex depinning behavior in thin films.

Contribution

It provides a detailed theoretical analysis of vortex-defect interactions, highlighting the role of core string formation in vortex depinning, which was not previously well understood.

Findings

Vortex core develops a string extending to the defect boundary.

Depinning is dominated by core string distortion.

Implications for experimental vortex manipulation.

Abstract

Using Ginzburg-Landau theory, we have performed detailed studies of vortices in the presence of artificial defect arrays, for a thin film geometry. We show that when a vortex approaches the vicinity of a defect, an abrupt transition occurs in which the vortex core develops a ``string'' extending to the defect boundary, while simultaneously the supercurrents and associated magnetic flux spread out and engulf the defect. Current induced depinning of vortices is shown to be dominated by the core string distortion in typical experimental situations. Experimental consequences of this unusual depinning behavior are discussed.