Skyrmion-induced bound states in a superconductor

TL;DR

This paper predicts skyrmion-induced bound states in a superconductor with potential implications for long-range skyrmion interactions, using T-matrix calculations and numerical modeling.

Contribution

It introduces the concept of skyrmion bound states in superconductors and analyzes their properties and potential role in skyrmion interactions.

Findings

Skyrmion bound states (SBS) are predicted to form in superconductors near skyrmions.

SBS wavefunctions decay with a power law spatially.

Overlap of SBS wavefunctions could mediate long-range skyrmion interactions.

Abstract

We consider a superconductor proximity coupled to a two-dimensional ferromagnetic film with a skyrmion texture. Using the T-matrix calculations and numerical modeling we calculate the spin-polarized local density of states in the superconductor in the vicinity of the skyrmion. We predict the skyrmion bound states (SBS) that are induced in the superconductor, similar to the well-known Yu-Shiba-Rusinov (YSR) states. The SBS wavefunctions have spatial power law decay. Presence of the SBS suggests the mechanism by which superconductivity could facilitate an effective long-range interaction between skyrmions when their SBS wavefunctions overlap.