Interaction-induced topological superconductivity in antiferromagnet-superconductor junctions

TL;DR

This paper predicts that antiferromagnet-superconductor junctions can host a robust one-dimensional topological superconducting state driven solely by electronic interactions, without requiring spin-orbit coupling or non-collinear magnetism.

Contribution

It introduces antiferromagnetic insulators as a new platform for interaction-driven topological superconductivity, demonstrating the emergence of topological states from repulsive interactions at the interface.

Findings

Topological superconductivity arises from repulsive interactions at the interface.

The topological gap saturates to that of the parent superconductor.

The platform does not require spin-orbit coupling or non-collinear magnetism.

Abstract

We predict that junctions between an antiferromagnetic insulator and a superconductor provide a robust platform to create a one-dimensional topological superconducting state. Its emergence does not require the presence of intrinsic spin-orbit coupling nor non-collinear magnetism, but arises solely from repulsive electronic interactions on interfacial solitonic states. We demonstrate that a topological superconducting state is generated by repulsive interactions at arbitrarily small coupling strength, and that the size of the topological gap rapidly saturates to the one of the parent trivial superconductor. Our results put forward antiferromagnetic insulators as a new platform for interaction-driven topological superconductivity.