Giant vortices, vortex rings and reentrant behavior in type-1.5 superconductors

TL;DR

This paper predicts novel vortex structures and complex phase behavior in bulk type-1.5 superconductors due to competing magnetic responses, revealing new phenomena without external pinning.

Contribution

It introduces the concept of group-stabilized giant vortices and vortex rings arising from intrinsic properties of type-1.5 superconductors within Ginzburg-Landau theory.

Findings

Giant vortices and vortex rings can form without extrinsic pinning.

A rich phase diagram with multiple transitions as temperature varies.

Vortex interactions are driven by the two-component order parameter.

Abstract

We predict that in a bulk type-1.5 superconductor the competing magnetic responses of the two components of the order parameter can result in a vortex interaction that generates group-stabilized giant vortices and unusual vortex rings in the absence of any extrinsic pinning or confinement mechanism. We also find within the Ginzburg-Landau theory a rich phase diagram with successions of behaviors like type-1 -> type-1.5 -> type-2 -> type-1.5 as temperature decreases.