Long-Range Fluctuation-Induced Attraction of Vortices to the Surface in Layered Superconductors

TL;DR

This paper reveals that in highly anisotropic layered superconductors, vortex lines experience a long-range attraction to the surface due to fluctuations, which can increase thermal fluctuations and cause flux creep.

Contribution

It introduces a new long-range fluctuation-induced attraction mechanism for vortex lines near surfaces in layered superconductors.

Findings

Long-range dipole-dipole attraction of vortex lines to the surface.

Enhanced thermal fluctuations extending beyond the penetration depth.

Potential for flux creep caused by fluctuation-induced surface attraction.

Abstract

It is shown that in extremely anisotropic layered superconductors the interaction of vortex lines with a parallel planar surface, which for straight lines along the c-axis decreases exponentially over the in-plane penetration depth $\lambda$, becomes a long-range dipole--dipole attraction when the vortex line is distorted randomly. This novel long-range fluctuation-induced attraction enhances the thermal fluctuations down to depths much larger than $\lambda$ and may lead to flux creep towards the surface.