title: Electric current focusing efficiency in a graphene electric lens.
abstract: In the present work, we study theoretically the electron wave's focusing phenomenon in a single-layered graphene pn junction (PNJ) and obtain the electric current density distribution of graphene PNJ, which is in good agreement with the qualitative result in previous numerical calculations (Cheianov et al 2007 Science, 315, 1252). In addition, we find that, for a symmetric PNJ, 1/4 of total electric current radiated from the source electrode can be collected by the drain electrode. Furthermore, this ratio reduces to 3/16 in a symmetric graphene npn junction. Our results obtained by the present analytical method provide a general design rule for an electric lens based on negative refractory index systems.
authors.affiliation: State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Science, Beijing 100190, People's Republic of China. muwh@itp.ac.cn
authors.forename: Weihua
authors.initials: W
authors.lastname: Mu
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang
authors.forename: Yunqing
authors.initials: Y
authors.lastname: Tang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Zhongcan
authors.initials: Z
authors.lastname: Ou-Yang
mesh_terms: D004553:Electric Conductivity; D004560:Electricity; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007909:Lenses; D008962:Models, Theoretical
chemical_list: D006108:Graphite