气候变化领域集成服务门户(CCPortal): Moiréless correlations in ABCA graphene

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DOI	10.1073/pnas.2017366118
	Moiréless correlations in ABCA graphene
	Kerelsky A.; Rubio-Verdú C.; Xian L.; Kennes D.M.; Halbertal D.; Finney N.; Song L.; Turkel S.; Wang L.; Watanabe K.; Taniguchi T.; Hone J.; Dean C.; Basov D.N.; Rubio A.; Pasupathy A.N.
发表日期	2021
ISSN	00278424
卷号	118 期号:4
英文摘要	Atomically thin van der Waals materials stacked with an interlayer twist have proven to be an excellent platform toward achieving gate-tunable correlated phenomena linked to the formation of flat electronic bands. In this work we demonstrate the formation of emergent correlated phases in multilayer rhombohedral graphene––a simple material that also exhibits a flat electronic band edge but without the need of having a moiré superlattice induced by twisted van der Waals layers. We show that two layers of bilayer graphene that are twisted by an arbitrary tiny angle host large (micrometer-scale) regions of uniform rhombohedral four-layer (ABCA) graphene that can be independently studied. Scanning tunneling spectroscopy reveals that ABCA graphene hosts an unprecedentedly sharp van Hove singularity of 3–5-meV half-width. We demonstrate that when this van Hove singularity straddles the Fermi level, a correlated many-body gap emerges with peak-to-peak value of 9.5 meV at charge neutrality. Mean-field theoretical calculations for model with short-ranged interactions indicate that two primary candidates for the appearance of this broken symmetry state are a charge-transfer excitonic insulator and a ferrimagnet. Finally, we show that ABCA graphene hosts surface topological helical edge states at natural interfaces with ABAB graphene which can be turned on and off with gate voltage, implying that small-angle twisted double-bilayer graphene is an ideal programmable topological quantum material. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Electron correlations; Graphene; Scanning tunneling microscopy; Scanning tunneling spectroscopy; Topology
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180900
作者单位	Department of Physics, Columbia University, New York, NY 10027, United States; Theory Department, Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, 22761, Germany; Frontier Research Center, Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China; Institut für Theorie der Statistischen Physik, Rheinisch-Westfälische Technische Hochschule Aachen University, Aachen, 52056, Germany; Jülich Aachen Research Alliance-Fundamentals of Future Information Technology, 52056, Aachen, Germany; Department of Mechanical Engineering, Columbia University, New York, NY 10027, United States; National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan; Center for Computational Quantum Physics, Flatiron Institute, New York, NY 10010, United States; Nano-Bio Spectroscopy Group, Departamento de Fisica de Materiales, Universidad del País Vasco, San Sebastian, 20018, Spain
推荐引用方式 GB/T 7714	Kerelsky A.,Rubio-Verdú C.,Xian L.,et al. Moiréless correlations in ABCA graphene[J],2021,118(4).
APA	Kerelsky A..,Rubio-Verdú C..,Xian L..,Kennes D.M..,Halbertal D..,...&Pasupathy A.N..(2021).Moiréless correlations in ABCA graphene.Proceedings of the National Academy of Sciences of the United States of America,118(4).
MLA	Kerelsky A.,et al."Moiréless correlations in ABCA graphene".Proceedings of the National Academy of Sciences of the United States of America 118.4(2021).