Single-layer graphene with electronic properties of a gated bilayer

We demonstrate that single-layer graphene exhibits the electronic structure of a bilayer when it is connected to two gated bilayers. The valence and conduction band continua as well as the energy gap characteristic of gated bilayer are induced in the single layer; the gap persists for distances separating the bilayers up to 20 nm. Most importantly, we report on the appearance of a topologically protected gapless state localized in a single graphene layer when the distant bilayers differ in the stacking order. The one-dimensional current in the topological state flows in single-layer graphene, and this finding suggests a new exploitation of graphene in nanoelectronics.