Vortices in magnetically coupled superconducting layered systems

TL;DR

This paper investigates vortex configurations in layered superconductors, highlighting how the absence of Josephson coupling allows for novel vortex structures, including vortices skipping surface layers, with size constraints affected by Josephson interactions.

Contribution

It introduces the concept that in layered superconductors without Josephson coupling, vortex configurations are less restricted, allowing for structures like vortices skipping layers, which are forbidden in bulk superconductors.

Findings

Vortices can skip surface layers in small samples.

Josephson coupling reduces the size R_c where skipping vortices occur.

Configurations forbidden in bulk are possible in layered systems.

Abstract

Pancake vortices in stacks of thin superconducting films or layers are considered. It is stressed that in the absence of Josephson coupling topological restrictions upon possible configurations of vortices are removed and various examples of structures forbidden in bulk superconductors are given. In particular, it is shown that vortices may skip surface layers in samples of less than a certain size R_c which might be macroscopic. The Josephson coupling suppresses R_c estimates.