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Catastrophe optics of caustics in single and bilayer graphene: Fine structure of caustics

Research output: Contribution to journalJournal article

Published

Journal publication date12/2010
Journalphysica status solidi (b)
Journal number11-12
Volume247
Number of pages4
Pages2949-2952
Original languageEnglish

Abstract

We theoretically study the scattering of a plane wave of a ballistic electron on a circular n-p junction (NPJ) in single and bilayer graphene. We compare the exact wave function inside the junction to that obtained from a semiclassical formula developed in catastrophe optics. In the semiclassical picture short wavelength electrons are treated as rays of particles that can get reflected and refracted at the NPJ according to Snell's law with negative refraction index. We show that for short wavelength and close to caustics this semiclassical approximation gives good agreement with the exact results in the case of single-layer graphene. We also verify the universal scaling laws that govern the shrinking rate and intensity divergence of caustics in the semiclassical limit. It is straightforward to generalize our semiclassical method to more complex geometries, offering a way to efficiently design and model graphene-based electron-optical systems. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim