Super-geometric electron focusing on the hexagonal Fermi surface of PdCoO2

Abstract

Ballistic electron beams in clean metals can be focused by passing currents through well designed contraptions, which is mostly done in isotropic materials described by a circular Fermi surface. Here, the authors demonstrate that the almost hexagonal Fermi surface of PdCoO2 gives rise to highly directional ballistic transport with enhanced electron self-focusing effects.