Two-dimensional topological semimetal states in monolayer Cu2Ge, Fe2Ge, and Fe2Sn

doi:10.1103/PhysRevB.101.165403

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	Two-dimensional topological semimetal states in monolayer Cu2Ge, Fe2Ge, and Fe2Sn
	Liu, Liangliang 1,2,3; Wang, Chongze 2,3; Li, Jiangxu 4; Chen, Xing-Qiu 4; Jia, Yu 1; Cho, Jun-Hyung 2,3
刊名	PHYSICAL REVIEW B
	2020-04-06
卷号	101 期号:16 页码:8
ISSN号	2469-9950
DOI	10.1103/PhysRevB.101.165403
通讯作者	Jia, Yu(jiayu@zzu.edu.cn)
英文摘要	Recent experimental realizations of the topological semimetal states in several monolayer systems are very attractive because of their exotic quantum phenomena and technological applications. Based on first-principles density-functional theory calculations including spin-orbit coupling, we here explore the drastically different two-dimensional (2D) topological semimetal states in three monolayers, Cu2Ge, Fe2Ge, and Fe2Sn, which are isostructural with a combination of the honeycomb Cu or Fe lattice and the triangular Ge or Sn lattice. We find that (i) the nonmagnetic (NM) Cu2Ge monolayer with a planar geometry exhibits the massive Dirac nodal lines, (ii) the ferromagnetic (FM) Fe2Ge monolayer with a buckled geometry exhibits the massive Weyl points, and (iii) the FM Fe2Sn monolayer with a planar geometry and an out-of-plane magnetic easy axis exhibits the massless Weyl nodal lines. It is therefore revealed that mirror symmetry cannot protect the fourfold-degenerate Dirac nodal lines in the NM Cu2Ge monolayer but preserves the doubly degenerate Weyl nodal lines in the FM Fe2Sn monolayer. Our findings demonstrate that the interplay of crystal symmetry, magnetic easy axis, and band topology is of importance for tailoring various 2D topological states in Cu2Ge, Fe2Ge, and Fe2Sn monolayers.
资助项目	National Research Foundation of Korea (NRF) - Korean government[2019R1A2C1002975] ; National Research Foundation of Korea (NRF) - Korean government[2016K1A4A3914691] ; National Research Foundation of Korea (NRF) - Korean government[2015M3D1A1070609] ; NSFC[11774078] ; Innovation Scientists and Technicians Troop Construction Projects of Henan Province[10094100510025] ; KISTI Supercomputing Center through the Strategic Support Program[KSC-2018-CRE-0063]
WOS研究方向	Materials Science ; Physics
语种	英语
出版者	AMER PHYSICAL SOC
WOS记录号	WOS:000523630200009
资助机构	National Research Foundation of Korea (NRF) - Korean government ; NSFC ; Innovation Scientists and Technicians Troop Construction Projects of Henan Province ; KISTI Supercomputing Center through the Strategic Support Program
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/138121]
专题	金属研究所_中国科学院金属研究所
通讯作者	Jia, Yu
作者单位	1.Henan Univ, Minist Educ, Key Lab Special Funct Mat, Kaifeng 475004, Peoples R China 2.Hanyang Univ, Dept Phys, Res Inst Nat Sci, 222 Wangsimni Ro, Seoul 04763, South Korea 3.Hanyang Univ, HYU HPSTAR CIS High Pressure Res Ctr, 222 Wangsimni Ro, Seoul 04763, South Korea 4.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Liu, Liangliang,Wang, Chongze,Li, Jiangxu,et al. Two-dimensional topological semimetal states in monolayer Cu2Ge, Fe2Ge, and Fe2Sn[J]. PHYSICAL REVIEW B,2020,101(16):8.
APA	Liu, Liangliang,Wang, Chongze,Li, Jiangxu,Chen, Xing-Qiu,Jia, Yu,&Cho, Jun-Hyung.(2020).Two-dimensional topological semimetal states in monolayer Cu2Ge, Fe2Ge, and Fe2Sn.PHYSICAL REVIEW B,101(16),8.
MLA	Liu, Liangliang,et al."Two-dimensional topological semimetal states in monolayer Cu2Ge, Fe2Ge, and Fe2Sn".PHYSICAL REVIEW B 101.16(2020):8.