Veselago Lens for Electrons: Focusing and Caustics in Graphene p-n Junctions

TL;DR

This paper predicts that a single p-n junction in graphene can focus electric current precisely or form caustics, enabling new electronic lens and beam-splitter designs in graphene transistors.

Contribution

It introduces the concept of electron focusing and caustics in graphene p-n junctions, with potential applications in electronic lens and beam-splitter engineering.

Findings

Precise electron focusing achievable at equal carrier densities.

Current distribution resembles optical caustics with different densities.

Potential for graphene-based electronic lens applications.

Abstract

The focusing of electric current by a single \textit{p-n} junction in graphene is predicted. We show that precise focusing can be achieved by fine-tuning the densities of carriers on the n- and p-sides of the junction to equal values, whereas the current distribution in junctions with different densities resembles caustics in optics. This finding can be utilized in the engineering of electronic lenses and focused beam-splitters using gate-controlled \textit{n-p-n} junctions in graphene-based transistors.