Magnetic flux induced topological superconductivity in magnetic atomic rings

TL;DR

This paper proposes a new model for one-dimensional topological superconductivity in magnetic atomic rings, utilizing magnetic fields and magnetic order orientations, expanding understanding beyond spin-orbit interaction-focused studies.

Contribution

It introduces a novel approach to realize topological superconductivity in magnetic rings using magnetic fields and order orientations, without relying solely on spin-orbit interactions.

Findings

Magnetic field or Rashba spin-orbit coupling can induce topological states.

Antiferromagnetic and ferromagnetic configurations are key to the model.

Perpendicular magnetic field orientation is crucial for topological superconductivity.

Abstract

There have been numerous studies on topological superconductivity in magnetic atomic chains deposited on s-wave superconductors. Most of these investigations have focused on spin-orbit interactions or helical spin orders. In this paper, we propose a model for achieving one-dimensional topological superconductivity in a magnetic atomic ring. This model utilizes a magnetic field and an antiferromagnetic/ferromagnetic order, under the condition that the magnetic field is perpendicular to the moments of the magnetic order. On a quasi-one-dimensional substrate surface, where the half-filled ring favors an antiferromagnetic configuration, we demonstrate that either the magnetic field itself or a Rashba spin-orbit coupling guarantees the perpendicularity. On a two-dimensional surface, where the ring favors ferromagnetic orders, the perpendicularity is achieved by introducing a minor Rashba spin-orbit coupling.