UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-22 1:28
 HOME     CONFERENCES     SEARCH            LOGIN     NEW USER     IMAGES   


Conference: Bucharest University Faculty of Physics 2013 Meeting


Section: Solid State Physics and Materials Science


Title:
Equivalence between graphene gated structures and bilayer graphene


Authors:
A. Zubarev, D. Dragoman


Affiliation:
Univ. Bucharest, Physics Dept., P.O. Box MG-11, 077125 Bucharest, Romania


E-mail


Keywords:
graphene, bilayer graphene, electron transmission


Abstract:
Graphene is one of the most interesting recently discovered materials. The study of graphene properties and the development of new applications of graphene-based structures receive a special attention from the scientific community. The reason is the expectation that graphene based devices, characterized by small dimensions, have high sensibility, small time of reaction and low energy consummation. In addition, multifunctional devices can be fabricated based on electron transmission modulation by an electric field applied on graphene-gated structures. Such gated graphene structures have applications as electronic switches and can be used for splitting, stirring or narrowing electronic beams. A suitable mathematical tool for computing the electron transmission through a gated graphene structure is the total transfer matrix method, the result of which is easily computable for periodic structures. However, in the presence of electric or magnetic fields this method is no longer appropriate because it requires a lot of computational resources. Therefore, in this paper we investigate the equivalence of a gated periodic structure in graphene with a single region of bilayer graphene, in which charge carriers have a finite effective mass. The possibility of this equivalence is suggested by the fact that the periodicity of the graphene structure affects the dispersion relation of charge carriers in graphene, such that inside the minibands their effective mass no longer vanishes but becomes finite. We have calculated the effective mass of charge carries in the graphene-based periodic structure and proved the equivalence with a bilayer graphene sheet with a similar electron wave number by showing that the transmission in both cases has a similar dependence on incidence angle and electron energy. This equivalence is useful for investigating of complex devices based on graphene heterostructures.