Intrinsic and tunable quantum anomalous Hall effect and magnetic topological phases in XYBi2Te5

TL;DR

This study uses first-principles calculations to explore magnetic and topological phases in XYBi2Te5 compounds, revealing potential for high-temperature quantum anomalous Hall effects and magnetic topological states.

Contribution

It identifies new magnetic topological phases in XYBi2Te5 compounds, including high-temperature quantum anomalous Hall states and magnetic Weyl semimetals, through first-principles calculations.

Findings

NiVBi2Te5 is a magnetic Weyl semimetal and Chern insulator with T_C ~150 K.

MnNiBi2Te5 has a Neel temperature over 200 K.

Some compounds exhibit intrinsic dynamic axion states and antiferromagnetic order above room temperature.

Abstract

By first-principles calculations, we study the magnetic and topological properties of XYBi2Te5-family (X, Y = Mn, Ni, V, Eu) compounds. The strongly coupled double magnetic atom-layers can significantly enhance the magnetic ordering temperature while keeping the topologically nontrivial properties. Particularly, NiVBi2Te5 is found to be a magnetic Weyl semimetal in bulk and a Chern insulator in thin film with both the Curie temperature (~150 K) and full gap well above 77 K. Ni2Bi2Te5, MnNiBi2Te5, NiVBi2Te5 and NiEuBi2Te5 exhibits intrinsic dynamic axion state. Among them, MnNiBi2Te5 has a Neel temperature over 200 K and Ni2Bi2Te5 even demonstrates antiferromagnetic order above room temperature. These results indicate an approach to realize high temperature quantum anomalous Hall effect and other topological quantum effects for practical applications.