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).

arXiv comment6 pages, 6 figures

References in corpus (16)

• 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
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• The quantum spin Hall effect and topological insulators
• 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
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Experimental demonstration of the topological surface states protected by the time-reversal symmetry
• STM imaging of electronic waves on the surface of Bi${}_2$Te${}_3$: topologically protected surface states and hexagonal warping effects
• Caustics due to Negative Refractive Index in Circular Graphene p-n Junctions
• Quasiparticle scattering in two dimensional helical liquid
• Quasiparticle Interference on the Surface of the Topological Insulator Bi${}_2$Te${}_3$
• Electronic structure near an impurity and terrace on the surface of a 3-dimensional topological insulator
• Spin-textures, Berry's phase and Quasiparticle Interference in Bi2Te3: A Topological Insulator with Warped Surface States
• Electron Flow in Circular n-p Junctions of Bilayer Graphene

Cited by in corpus (11)

• In-plane Topological p-n Junction in the Three-Dimensional Topological Insulator Bi${}_{2-x}$Sb${}_x$Te${}_{3-y}$Se${}_y$
• Selective focusing of electrons and holes in a graphene-based superconducting lens
• Intraband electron focusing in bilayer graphene
• Dynamics of domain-wall Dirac fermions on a topological insulator: a chiral fermion beam splitter
• Spectroscopy of snake states using a graphene Hall bar
• Electron beam splitting at topological insulator surface states and a proposal for electronic Goos-Hanchen shift measurement
• A corner reflector of graphene Dirac fermions as a phonon-scattering sensor
• Veselago focusing of anisotropic massless Dirac fermions
• Graphene Hall bar with an asymmetric pn-junction
• Bilayer graphene Hall bar with a pn-junction
• Electric Current Focusing Efficiency in Graphene Electric Lens