Cloning the Dirac cones of bilayer graphene to the zone center by selenium adsorption

Abstract

Dirac cones can foster extraordinary electronic effects, as exemplified by the case of graphene layers. Angle-resolved photoemission reveals that adsorption of selenium (Se) vapor on bilayer graphene creates a symmetric hybrid clone of the Dirac cones at the zone center. A detailed analysis aided by first-principles calculations shows that the adsorbed layer consists of an ordered array of Se8 molecules. The uncovered cloning mechanism illustrates a method to generate electronic features of scientific and technological interests by gentle surface modification via van der Waals adsorption.