Experimental evidence for orbital magnetic moments generated by moire-scale current loops in twisted bilayer graphene

doi:10.1103/PhysRevB.102.121406

	Experimental evidence for orbital magnetic moments generated by moire-scale current loops in twisted bilayer graphene
	Li, Si-Yu 1,2; Zhang, Yu 2; Ren, Ya-Ning 2; Liu, Jianpeng3,4 ; Dai, Xi 4; He, Lin 2
	2020-09-18
发表期刊	PHYSICAL REVIEW B (IF:3.2[JCR-2023],3.3[5-Year])
ISSN	2469-9950
卷号	102 期号:12
DOI	10.1103/PhysRevB.102.121406
摘要	Electron-electron (e-e) interactions in the twisted bilayer graphene (TBG) near the magic angle similar to 1.1 degrees can lift the valley degeneracy, allowing for the realization of orbital magnetism and topological phases. However, direct measurement of the orbital-based magnetism in the TBG is still lacking up to now. Here we report evidence for orbital magnetic moment generated by the moire-scale current loops in a TBG with a twist angle theta similar to 1.68 degrees. The valley degeneracy of the 1.68 degrees TBG is removed by e-e interactions when its low-energy Van Hove singularity (VHS) is nearly half filled. A large and linear response of the valley splitting to magnetic fields is observed, which we interpret as arising from the coupling to the large orbital magnetic moment induced by chiral current loops circulating in the moire pattern. According to our experiment, the orbital magnetic moment is about 10.7 mu(B) per moire supercell. Our result paves the way to explore magnetism that is purely orbital in a slightly twisted graphene system.
收录类别	SCI ; SCIE ; EI
语种	英语
资助项目	National Natural Science Foundation of China[11974050][11674029]
WOS研究方向	Materials Science ; Physics
WOS类目	Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter
WOS记录号	WOS:000570979200001
出版者	AMER PHYSICAL SOC
引用统计	正在获取...
文献类型	期刊论文
条目标识符	https://kms.shanghaitech.edu.cn/handle/2MSLDSTB/123552
专题	物质科学与技术学院物质科学与技术学院_PI研究组_刘健鹏组
通讯作者	Liu, Jianpeng; He, Lin
作者单位	1.Hunan Univ, Coll Mat Sci & Engn, Key Lab Micronano Phys & Technol Hunan Prov, Changsha 410082, Hunan, Peoples R China; 2.Beijing Normal Univ, Ctr Adv Quantum Studies, Dept Phys, Beijing 100875, Peoples R China; 3.ShanghaiTech Univ, Sch Phys Sci & Technol, Shanghai 200031, Peoples R China; 4.Hong Kong Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong, Peoples R China
通讯作者单位	物质科学与技术学院
推荐引用方式 GB/T 7714	Li, Si-Yu,Zhang, Yu,Ren, Ya-Ning,et al. Experimental evidence for orbital magnetic moments generated by moire-scale current loops in twisted bilayer graphene[J]. PHYSICAL REVIEW B,2020,102(12).
APA	Li, Si-Yu,Zhang, Yu,Ren, Ya-Ning,Liu, Jianpeng,Dai, Xi,&He, Lin.(2020).Experimental evidence for orbital magnetic moments generated by moire-scale current loops in twisted bilayer graphene.PHYSICAL REVIEW B,102(12).
MLA	Li, Si-Yu,et al."Experimental evidence for orbital magnetic moments generated by moire-scale current loops in twisted bilayer graphene".PHYSICAL REVIEW B 102.12(2020).