title: Zero Landau level in folded graphene nanoribbons.
abstract: Graphene nanoribbons can be folded into a double layer system keeping the two layers decoupled. In the quantum Hall regime folds behave as a new type of Hall bar edge. We show that the symmetry properties of the zero Landau level in metallic nanoribbons dictate that the zero energy edge states traversing a fold are perfectly transmitted onto the opposite layer. This result is valid irrespective of fold geometry, magnetic field strength, and crystallographic orientation of the nanoribbon. Backscattering suppression on the N=0 Hall plateau is ultimately due to the orthogonality of forward and backward channels, much like in the Klein paradox.
authors.affiliation: Instituto de Ciencia de Materiales de Madrid (CSIC), Cantoblanco, 28049 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Prada
authors.forename: P
authors.initials: P
authors.lastname: San-Jose
authors.forename: L
authors.initials: L
authors.lastname: Brey