Dissipation of moving vortices in thin films

TL;DR

This paper analyzes how moving vortices in thin superconducting films dissipate energy, revealing a minimum dissipation configuration where vortices tend to form chains aligned with their velocity.

Contribution

It introduces a detailed theoretical analysis of vortex dissipation in thin films, identifying conditions for minimal energy loss and vortex chain formation.

Findings

Minimum dissipation occurs when vortices are separated by approximately 2.2 times the Pearl length.

Vortices tend to align in chains along the direction of motion.

The study provides insights into vortex dynamics relevant for superconducting film applications.

Abstract

Moving vortices in thin superconducting films are considered within the time-dependent London description. The dissipation due to out-of-core normal excitations for two vortices moving together turns out to have a minimum for the separation vector $\bm a$ parallel to the velocity and equal to $a_m \approx 2.2\, \Lambda$, where $\Lambda $ is the Pearl length. The minimum entropy production suggests that moving vortices should have a tendency to form chains along the velocity with a period of the order $a_m$.