Bipolarized Weyl semimetals and quantum crystal valley Hall effect in two-dimensional altermagnetic materials

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Tan, Chao-Yang, Gao, Ze-Feng, Yang, Huan-Cheng, Liu, Kai, Guo, Peng-Jie, Lu, Zhong-Yi
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911930632896512
author Tan, Chao-Yang
Gao, Ze-Feng
Yang, Huan-Cheng
Liu, Kai
Guo, Peng-Jie
Lu, Zhong-Yi
author_facet Tan, Chao-Yang
Gao, Ze-Feng
Yang, Huan-Cheng
Liu, Kai
Guo, Peng-Jie
Lu, Zhong-Yi
contents Magnetism and topology are two major areas of condensed matter physics. The combination of magnetism and topology gives rise to more novel physical effects, which have attracted strongly theoretical and experimental attention. Recently, the concept of altermagnetism has been introduced, characterized by a dual nature: real-space antiferromagnetism and reciprocal-space anisotropic spin polarization. The amalgamation of altermagnetism with topology may lead to the emergence of previously unobserved topological phases and the associated physical effects. In this study, utilizing a four-band lattice model that incorporates altermagnetism and spin group symmetry, we demonstrate that type-I, type-II, and type-III bipolarized Weyl semimetals can exist in altermagnetic systems. Through the first-principles electronic structure calculations, we predict four ideal two-dimensional type-I altermagnetic bipolarized Weyl semimetals Fe$_2$WTe$_4$ and Fe$_2$MoZ$_4$ (Z=S,Se,Te). More significantly, we introduce the quantum crystal valley Hall effect, a phenomenon achievable in three of these materials namely Fe$_2$WTe$_4$, Fe$_2$MoS$_4$, and Fe$_2$MoTe$_4$, when spin-orbit coupling is considered. Furthermore, these materials have the potential to transition from a quantum crystal valley Hall phase to a Chern insulator phase under strain. In contrast, Fe$_2$MoSe$_4$ remains to be a Weyl semimetal under spin-orbit coupling but is distinguished by possessing only a single pair of Weyl points. Additionally, the position, polarization, and number of Weyl points in Fe$_2$WTe$_4$ and Fe$_2$MoZ$_4$ can be manipulated by adjusting the direction of the Néel vector. Consequently, Fe$_2$WTe$_4$ and Fe$_2$MoZ$_4$ emerge as promising experimental platforms for investigating the distinctive physical attributes of various altermagnetic topological phases.
format Preprint
id arxiv_https___arxiv_org_abs_2406_16603
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Bipolarized Weyl semimetals and quantum crystal valley Hall effect in two-dimensional altermagnetic materials
Tan, Chao-Yang
Gao, Ze-Feng
Yang, Huan-Cheng
Liu, Kai
Guo, Peng-Jie
Lu, Zhong-Yi
Materials Science
Magnetism and topology are two major areas of condensed matter physics. The combination of magnetism and topology gives rise to more novel physical effects, which have attracted strongly theoretical and experimental attention. Recently, the concept of altermagnetism has been introduced, characterized by a dual nature: real-space antiferromagnetism and reciprocal-space anisotropic spin polarization. The amalgamation of altermagnetism with topology may lead to the emergence of previously unobserved topological phases and the associated physical effects. In this study, utilizing a four-band lattice model that incorporates altermagnetism and spin group symmetry, we demonstrate that type-I, type-II, and type-III bipolarized Weyl semimetals can exist in altermagnetic systems. Through the first-principles electronic structure calculations, we predict four ideal two-dimensional type-I altermagnetic bipolarized Weyl semimetals Fe$_2$WTe$_4$ and Fe$_2$MoZ$_4$ (Z=S,Se,Te). More significantly, we introduce the quantum crystal valley Hall effect, a phenomenon achievable in three of these materials namely Fe$_2$WTe$_4$, Fe$_2$MoS$_4$, and Fe$_2$MoTe$_4$, when spin-orbit coupling is considered. Furthermore, these materials have the potential to transition from a quantum crystal valley Hall phase to a Chern insulator phase under strain. In contrast, Fe$_2$MoSe$_4$ remains to be a Weyl semimetal under spin-orbit coupling but is distinguished by possessing only a single pair of Weyl points. Additionally, the position, polarization, and number of Weyl points in Fe$_2$WTe$_4$ and Fe$_2$MoZ$_4$ can be manipulated by adjusting the direction of the Néel vector. Consequently, Fe$_2$WTe$_4$ and Fe$_2$MoZ$_4$ emerge as promising experimental platforms for investigating the distinctive physical attributes of various altermagnetic topological phases.
title Bipolarized Weyl semimetals and quantum crystal valley Hall effect in two-dimensional altermagnetic materials
topic Materials Science
url https://arxiv.org/abs/2406.16603