title: Hofstadter Butterfly and Many-Body Effects in Epitaxial Graphene Superlattice.
abstract: Graphene placed on hexagonal boron nitride (h-BN) has received a wide range of interest due to the improved electrical performance and rich physics from the interface, especially the emergence of superlattice Dirac points as well as Hofstadter butterfly in high magnetic field. Instead of transferring graphene onto h-BN, epitaxial growth of graphene directly on a single-crystal h-BN provides an alternative and promising way to study these interesting superlattice effects due to their precise lattice alignment. Here we report an electrical transport study on epitaxial graphene superlattice on h-BN with a period of ∼15.6 nm. The epitaxial graphene superlattice is clean, intrinsic, and of high quality with a carrier mobility of ∼27 000 cm(2) V(-1) s(-1), which enables the observation of Hofstadter butterfly features originated from the superlattice at a magnetic field as low as 6.4 T. A metal-insulator transition and magnetic field dependent Fermi velocity were also observed, suggesting prominent electron-electron interaction-induced many-body effects.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.|Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité , 24 rue Lhomond, 75231 Paris Cedex 05, France.
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University , Shanghai 200433, China.
authors.forename: Guorui
authors.initials: G
authors.lastname: Chen
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wu
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Guibai
authors.initials: G
authors.lastname: Xie
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Cheng
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Duoming
authors.initials: D
authors.lastname: Wang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Yang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Dongxia
authors.initials: D
authors.lastname: Shi
authors.affiliation: Advanced Materials Laboratory, National Institute for Materials Science , 1-1 Namiki, Tsukuba, 305-0044, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Advanced Materials Laboratory, National Institute for Materials Science , 1-1 Namiki, Tsukuba, 305-0044, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité , 24 rue Lhomond, 75231 Paris Cedex 05, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Voisin
authors.affiliation: Laboratoire Pierre Aigrain, Ecole Normale Supérieure-PSL Research University, CNRS, Université Pierre et Marie Curie-Sorbonne Universités, Université Paris Diderot-Sorbonne Paris Cité , 24 rue Lhomond, 75231 Paris Cedex 05, France.
authors.forename: Bernard
authors.initials: B
authors.lastname: Plaçais
authors.affiliation: State Key Laboratory of Surface Physics and Department of Physics, Fudan University , Shanghai 200433, China.
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Zhang
keywords: Fermi velocity; Graphene superlattice; Hofstadter butterfly; many-body effects; metal−insulator transition