Quantum Anomalous Hall Effect in a Perovskite and Inverse-Perovskite Sandwich Structure

TL;DR

This paper predicts a novel topologically nontrivial quantum anomalous Hall phase in a carefully designed sandwich structure combining a G-type AFM Mott insulator and an inverse-perovskite material, supported by first-principles calculations.

Contribution

It introduces a new heterostructure design exhibiting quantum anomalous Hall effect with potential for experimental realization.

Findings

Supports spin-polarized, dissipationless edge currents

Predicted topologically nontrivial phase with nonzero charge and spin Chern numbers

Materials are stable and compatible for synthesis

Abstract

Based on first-principles calculations, we propose a sandwich structure composed of a G-type anti-ferromagnetic (AFM) Mott insulator LaCrO$_3$ grown along the [001] direction with one atomic layer replaced by an inverse-perovskite material Sr$_3$PbO. We show that the system is in a topologically nontrivial phase characterized by simultaneous nonzero charge and spin Chern numbers, which can support a spin-polarized and dissipationless edge current in a finite system. Since these two materials are stable in bulk and match each other with only small lattice distortions, the composite material is expected easy to synthesize.