5d orbital Induced Room Temperature Quantum Anomalous Hall Effect in TbCl

TL;DR

This paper proposes monolayer TbCl as a promising material for realizing the quantum anomalous Hall effect at room temperature, with large topological gaps and high Curie temperature confirmed through advanced computational methods.

Contribution

It introduces monolayer TbCl as a new candidate for room temperature QAH effect, supported by comprehensive DFT+U, HSE06, and DMFT calculations showing its topological and magnetic properties.

Findings

Hall conductivity of -e^2/h per layer in TbCl

Large topological band gap of 42.8 meV

High Curie temperature of approximately 457K

Abstract

Following the experimental realization of Quantum anomalous Hall (QAH) effect in thin films of chromium-doped (Bi,Sb)$_2$Te$_3$, enhancing the work temperature of QAH effect has emerged as a significant and challenging task. Here we demonstrate monolayer TbCl as a promising candidate to realize the room temperature QAH effect. Using DFT+U method, double checked by HSE06 and DMFT calculations, we identify the Hall conductivity $G = -e^2/h$ per layer in three-dimensional ferromagnetic insulator TbCl, which is a weakly stacking of QAH layers. The monolayer TbCl inherits the magnetic and topological properties, exhibiting the QAH effect with Chern number $C$=-1. The large topological band gap reaches 42.8 meV, which is beyond room temperatue. The extended 5$d$ electrons lead to sizable exchange and superexchange interactions, resulting in a high Curie temperature $T_c$$\sim$457K. All these features demonstrate that monolayer TbCl will provide an ideal platform to realize the room temperature QAH effect.