Conditions for non-monotonic vortex interaction in two-band superconductors

TL;DR

This paper presents a semi-analytic approach to two-band Ginzburg-Landau theory, revealing conditions for non-monotonic vortex interactions in two-band superconductors, influenced by interface energy and a modified Ginzburg-Landau parameter.

Contribution

It introduces a semi-analytic method to predict vortex interactions in two-band superconductors, highlighting the role of interface energy and a modified Ginzburg-Landau parameter.

Findings

Short-range vortex interaction depends on interface energy sign.

Long-range interaction is governed by a modified Ginzburg-Landau parameter.

Non-monotonic, temperature-dependent vortex interactions are possible.

Abstract

We describe a semi-analytic approach to the two-band Ginzburg-Landau theory, which predicts the behavior of vortices in two-band superconductors. We show that the character of the short-range vortex-vortex interaction is determined by the sign of the normal domain - superconductor interface energy, in analogy with the conventional differentiation between type-I and type-II superconductors. However, we also show that the long-range interaction is determined by a modified Ginzburg-Landau parameter $\kappa^*$, different from the standard $\kappa$ of a bulk superconductor. This opens the possibility for non-monotonic vortex-vortex interaction, which is temperature-dependent, and can be further tuned by alterations of the material on the microscopic scale.