Bilayer graphene Origami: curvature-induced p-n junctions
Abstract
A massive quantum particle on a two-dimensional curved surface experiences a surface-geometry induced attractive potential that is characterized by the radii of curvature at a given point. With bilayer graphene sheets and carbon nano-ribbons in mind, we obtain the geometric potential VG for several surface shapes. Under appropriate conditions that we discuss in detail, this potential suppresses the local Fermi energy. Therefore, we argue that in zero band-gap materials with a quadratic band structure, it will create p- and n-type regions. We discuss the consequences of this result, and suggest that surface curvature can provide a novel avenue to create p-n junctions and, in general, to control local electronic properties in bilayer graphene sheets.