title: Breakdown of the interlayer coherence in twisted bilayer graphene.
abstract: Coherent motion of electrons in Bloch states is one of the fundamental concepts of charge conduction in solid-state physics. In layered materials, however, such a condition often breaks down for the interlayer conduction, when the interlayer coupling is significantly reduced by, e.g., a large interlayer separation. We report that complete suppression of coherent conduction is realized even in an atomic length scale of layer separation in twisted bilayer graphene. The interlayer resistivity of twisted bilayer graphene is much higher than the c-axis resistivity of Bernal-stacked graphite and exhibits strong dependence on temperature as well as on external electric fields. These results suggest that the graphene layers are significantly decoupled by rotation and incoherent conduction is a main transport channel between the layers of twisted bilayer graphene.
authors.affiliation: Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
authors.forename: Youngwook
authors.initials: Y
authors.lastname: Kim
authors.forename: Hoyeol
authors.initials: H
authors.lastname: Yun
authors.forename: Seung-Geol
authors.initials: SG
authors.lastname: Nam
authors.forename: Minhyeok
authors.initials: M
authors.lastname: Son
authors.forename: Dong Su
authors.initials: DS
authors.lastname: Lee
authors.forename: Dong Chul
authors.initials: DC
authors.lastname: Kim
authors.forename: S
authors.initials: S
authors.lastname: Seo
authors.forename: Hee Cheul
authors.initials: HC
authors.lastname: Choi
authors.forename: Hu-Jong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Sang Wook
authors.initials: SW
authors.lastname: Lee
authors.forename: Jun Sung
authors.initials: JS
authors.lastname: Kim