Electric current focusing efficiency in a graphene electric lens

• Published in: Journal of physics. Condensed matter Vol. 23; no. 49; pp. 495302 - 6
• Main Authors: Mu, Weihua, Zhang, Gang, Tang, Yunqing, Wang, Wei, Ou-Yang, Zhongcan
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 14.12.2011; Institute of Physics
• Subjects: Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Design engineering; Drains; Electric Conductivity; Electric current; Electricity; Electrodes; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Graphene; Graphite - chemistry; Humans; Lenses; Mathematical analysis; Models, Theoretical; Physics; Graphene; Focusing; p n junctions; Analytical method; Numerical method; Electron lenses; Density distribution; Negative refraction; Electric currents; Current density
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/23/49/495302

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.