磁性外尔半金属的发现  

Discovery of magnetic Weyl semimetal

作　　者：刘德发 LIU Defa(Department of Physics,Key Laboratory of Multiscale Spin Physics,Ministry of Education,Beijing Normal University,100875,Beijing,China)

机构地区：[1]北京师范大学物理学系,教育部多尺度自旋物理重点实验室,北京100875

出　　处：《北京师范大学学报（自然科学版）》2023年第6期844-851,共8页Journal of Beijing Normal University(Natural Science)

基　　金：国家高层次人才青年项目;中央高校基本科研业务费专项资金资助。

摘　　要：外尔半金属是一种新奇的拓扑量子物态,具有手性相反的外尔点和表面态费米弧结构.这种独特的电子结构赋予了外尔半金属奇特的物理性质,如手性反常和量子振荡等.外尔半金属按照对称性不同的破缺方式可以分为中心反演对称性破缺的非磁性外尔半金属和时间反演对称性破缺的磁性外尔半金属.其中磁性外尔半金属的电子结构对磁结构的具体形式非常敏感,因此可以通过外加磁场或电场来改变磁矩的方向,以达到操控其拓扑相变和物理性质的变化.这一特性在自旋电子学领域具有潜在的应用价值.具有笼目结构的铁磁体Co3Sn2S2是首个被实验证实的磁性外尔半金属.本文主要综述了磁性外尔半金属Co3Sn2S2的发现,包括输运性质、理论计算和电子结构的测量,并对磁性外尔半金属未来的研究进行了展望.Weyl semimetal is a novel topological quantum state with emergent relativistic Weyl fermions of opposite chiralities and surface Fermi arcs in the electronic structure.Such distinct electronic structure leads to many exotic physical properties,such as chiral anomaly and quantum oscillations.Based on the symmetry broken,Weyl semimetal can be classified as inversion symmetry breaking non-magnetic Weyl semimetal,and time-reversal symmetry breaking magnetic Weyl semimetal.The latter is very sensitive to magnetic structure so that the manipulation of topological phase transition and physical properties can be induced by external magnetic or electric field.This has great potentials for applications in the field of spintronics.The kagome ferromagnet Co3Sn2S2 is the first experimentally discovered magnetic Weyl semimetal.Its discovery is reviewed here,with emphasis on transport properties,theoretical calculations and measurements of electronic structures.The future of the study of the magnetic semimetal is discussed.

关 键 词：磁性外尔半金属 费米弧 自旋轨道耦合 拓扑相变 电子结构 角分辨光电子能谱 

分 类 号：O469[理学—凝聚态物理]