Flat-lens focusing of electrons on the surface of a topological insulator

Abstract

We propose the implementation of an electronic Veselago lens on the conducting surface of a three-dimensional topological insulator (such as Bi2Te3). The negative refraction needed for such a flat lens results from the sign change of the curvature of the Fermi surface, changing from a circular to a snowflake-like shape across a sufficiently large electrostatic potential step. No interband transition (as in graphene) is needed. For this reason, and because the topological insulator provides protection against backscattering, the potential step is able to focus a broad range of incident angles. We calculate the quantum interference pattern produced by a point source, generalizing the analogous optical calculation to include the effect of a noncircular Fermi surface (having a nonzero conic constant).

6 pages, 6 figures

References in corpus (7)

• Chiral tunneling and the Klein paradox in graphene
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Veselago Lens for Electrons: Focusing and Caustics in Graphene p-n Junctions
• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
• Caustics due to Negative Refractive Index in Circular Graphene p-n Junctions
• Electron Flow in Circular n-p Junctions of Bilayer Graphene

Cited by in corpus (4)

• Selective focusing of electrons and holes in a graphene-based superconducting lens
• Intraband electron focusing in bilayer graphene
• A corner reflector of graphene Dirac fermions as a phonon-scattering sensor
• Electron beam splitting at topological insulator surface states and a proposal for electronic Goos-Hanchen shift measurement