Two-dimensional antiferromagnetic Dirac fermions in monolayer TaCoTe2

被引：36

作者：

Li, Si ^{[1
,2
,3
,4
]}

Liu, Ying ^{[4
,5
]}

Yu, Zhi-Ming ^{[4
]}

Jiao, Yalong ^{[4
]}

Guan, Shan ^{[6
]}

Sheng, Xian-Lei ^{[4
,7
]}

Yao, Yugui ^{[2
,3
]}

Yang, Shengyuan A. ^{[4
,8
]}

机构：

[1] Hunan Normal Univ, Sch Phys & Elect, Changsha 410081, Hunan, Peoples R China

[2] Beijing Inst Technol, Key Lab Adv Optoelect Quantum Architecture & Meas, Beijing Key Lab Nanophoton & Ultrafine Optoelect, Beijing 100081, Peoples R China

[3] Beijing Inst Technol, Sch Phys, Beijing 100081, Peoples R China

[4] Singapore Univ Technol & Design, Res Lab Quantum Mat, Singapore 487372, Singapore

[5] Univ Wurzburg, Inst Theoret Phys & Astrophys, D-97074 Wurzburg, Germany

[6] Chinese Acad Sci, Inst Semicond, State Key Lab Superlattices & Microstruct, Beijing 100083, Peoples R China

[7] Beihang Univ, Dept Phys, Key Lab Micronano Measurement Manipulat & Phys MO, Beijing 100191, Peoples R China

[8] Nanjing Normal Univ, Ctr Quantum Transport & Thermal Energy Sci, Sch Phys & Technol, Nanjing 210023, Jiangsu, Peoples R China

来源：

PHYSICAL REVIEW B | 2019年 / 100卷 / 20期

基金：

国家重点研发计划;

关键词：

Ground state - Antiferromagnetism - Calculations - Monolayers - Dispersions;

D O I：

10.1103/PhysRevB.100.205102

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Dirac points in two-dimensional (2D) materials have been a fascinating subject of research. Recently, it has been theoretically predicted that Dirac points may also be stabilized in 2D magnetic systems. However, it remains a challenge to identify concrete 2D materials which host such magnetic Dirac points. Here, based on firstprinciples calculations and theoretical analysis, we propose a stable 2D material, the monolayer TaCoTe2, as an antiferromagnetic (AFM) 2D Dirac material. We show that it has an AFM ground state with an out-of-plane Neel vector. It hosts a pair of 2D AFM Dirac points on the Fermi level in the absence of spin-orbit coupling (SOC). When the SOC is considered, a small gap is opened at the original Dirac points. Meanwhile, another pair of Dirac points appear on the Brillouin zone boundary below the Fermi level, which are robust under SOC and have a type-II dispersion. Such a type-II AFM Dirac point has not been observed before. We further show that the location of this Dirac point as well as its dispersion type can be controlled by tuning the Neel vector orientation.

引用

页数：8