Intrinsic ferromagnetic axion states and a single pair of Weyl fermions in the stable-state Mn\emph{X}$_{2}$\emph{B}$_{2}$\emph{T}$_{6}$-family materials

TL;DR

This paper introduces a new family of MnX2B2T6-B materials that are stable and exhibit intrinsic ferromagnetic axion insulator and Weyl semimetal states, with potential for exploring topological magnetoelectric effects.

Contribution

The study identifies a stable class of MnX2B2T6-B materials that host both ferromagnetic axion insulator and Weyl semimetal phases with a single pair of Weyl points, advancing topological material research.

Findings

Discovery of stable MnX2B2T6-B compounds with intrinsic FM axion insulator states.

Identification of MnSn2Sb2Te6-B as an intrinsic Weyl semimetal with a single pair of Weyl points.

Provision of a platform for studying topological magnetoelectric effects.

Abstract

The intrinsic ferromagnetic (FM) axion insulators and Weyl semimetals (WSMs) with only single pair of Weyl points have drawn intensive attention but so far remain rare and elusive in real materials. Here, we propose a new class of Mn\emph{X}$_{2}$\emph{B}$_{2}$\emph{T}$_{6}$-B (\emph{X}=Ge, Sn, or Pb; \emph{B}=Sb or Bi; \emph{T}=Se or Te) family that is the stable structural form of this system. We find that the Mn\emph{X}$_{2}$\emph{B}$_{2}$\emph{T}$_{6}$-B family has not only the intrinsic FM axion insulators MnGe$_{2}$Bi$_{2}$Te$_{6}$-B, MnSn$_{2}$Bi$_{2}$Te$_{6}$-B, and MnPb$_{2}$Bi$_{2}$Te$_{6}$-B, but also the intrinsic WSM MnSn$_{2}$Sb$_{2}$Te$_{6}$-B with only a single pair of Weyl points. Thus, the Mn\emph{X}$_{2}$\emph{B}$_{2}$\emph{T}$_{6}$-B family can provide an ideal platform to explore the exotic topological magnetoelectric effect and the intrinsic properties related to Weyl points.