Electrically Tunable Topological State in [111] Perovskite Materials with Antiferromagnetic Exchange Field

TL;DR

This paper proposes a method to realize a topological state with tunable spin-polarized edge currents in [111] perovskite materials, enabling potential advances in spintronics through electric field control.

Contribution

It demonstrates, via first-principles calculations, that perovskite G-type antiferromagnetic insulators can host electrically tunable topological states with robust spin-polarized edge currents.

Findings

Realization of topological states in perovskite G-type antiferromagnetic insulators.

Spin polarization of edge currents can be controlled by electric field inversion.

Edge currents are robust against defects.

Abstract

A topological state with simultaneous nonzero Chern number and spin Chern number is possible for electrons on honeycomb lattice based on band engineering by staggered electric potential and antiferromagnetic exchange field in presence of intrinsic spin-orbit coupling. With first principles calculation we confirm that the scheme can be realized by material modification in perovskite G-type antiferromagnetic insulators grown along [111] direction, where d electrons hop on a single buckled honeycomb lattice. This material is ideal for spintronics applications, since it provides a spin-polarized quantized edge current, robust to both nonmagnetic and magnetic defects, with the spin polarization tunable by inverting electric field.