Type-1.5 Superconducting State from an Intrinsic Proximity Effect in Two-Band Superconductors

TL;DR

This paper demonstrates that in two-band superconductors, a small interband proximity effect can cause long-range vortex attraction, leading to unique magnetic responses and phase separation phenomena.

Contribution

It reveals how a minor interband proximity effect induces a qualitative change in vortex interactions, resulting in a novel superconducting state.

Findings

Long-range intervortex attraction in two-band superconductors

Phase separation into Meissner domains and vortex droplets

Unusual magnetic response at low fields

Abstract

We show that in multiband superconductors even small interband proximity effect can lead to a qualitative change in the interaction potential between superconducting vortices by producing long-range intervortex attraction. This type of vortex interaction results in unusual response to low magnetic fields leading to phase separation into domains of a two-component Meissner states and vortex droplets.