Dresden 2017 – wissenschaftliches Programm
DS 9.1: Vortrag
Montag, 20. März 2017, 15:00–15:15, HSZ 204
Creating and steering highly directional electron beams in graphene — Ming-Hao Liu1,2, •Cosimo Gorini1, and Klaus Richter1 — 1Institut für Theoretische Physik, Universität Regensburg, Regensburg, Germany — 2Department of Physics, National Cheng Kung University, Tainan, Taiwan
We put forward a concept to create highly collimated, non-dispersive electron beams in pseudo-relativistic 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 a few Fermi wave lengths, 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.
 M.-H. Liu, C. Gorini, K. Richter, arXiv:1608.01730.