Topological States in Ferromagnetic CdO/EuO Superlattices and Quantum Wells

TL;DR

This paper predicts that ferromagnetic CdO/EuO superlattices are Weyl semimetals with potential for quantum anomalous Hall effects, based on ab initio calculations and an effective model.

Contribution

It introduces the first ab initio demonstration of Weyl semimetal states in ferromagnetic CdO/EuO superlattices and models the spin-polarized band inversion mechanism.

Findings

CdO/EuO superlattice is a Weyl semimetal with two Weyl nodes.

Quantum wells exhibit the quantum anomalous Hall state.

Effective model explains spin-polarized band inversion.

Abstract

Based on ab initio calculations, we demonstrate that the ferromagnetic CdO/EuO superlattice is a simple Weyl semimetal with two linear Weyl nodes in the Brillouin zone, and the corresponding CdO/EuO quantum well realizes the stichometric quantum anomalous Hall state without random magnetic doping. In addition, a simple effective model is presented to describe the basic mechanism of spin polarized band inversion in this system.