title: Creating and Steering Highly Directional Electron Beams in Graphene.
abstract: We put forward a concept to create highly collimated, nondispersive electron beams in pseudorelativistic Dirac materials such as graphene or topological insulator surfaces. Combining negative refraction and Klein collimation at a parabolic pn junction, the proposed lens generates beams, as narrow as the focal length, that stay focused over scales of several microns and can be steered by a magnetic field without losing collimation. We demonstrate the lens capabilities by applying it to two paradigmatic settings of graphene electron optics: We propose a setup for observing high-resolution angle-dependent Klein tunneling, and, exploiting the intimate quantum-to-classical correspondence of these focused electron waves, we consider high-fidelity transverse magnetic focusing accompanied by simulations for current mapping through scanning gate microscopy. Our proposal opens up new perspectives for next-generation graphene electron optics experiments.
authors.affiliation: Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany.
authors.forename: Ming-Hao
authors.initials: MH
authors.lastname: Liu
authors.affiliation: Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany.
authors.forename: Cosimo
authors.initials: C
authors.lastname: Gorini
authors.affiliation: Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Richter