Current at a distance and resonant transparency in Weyl semimetals

TL;DR

This paper proposes robust, experimentally accessible methods to directly probe Fermi arcs in Weyl semimetals using magnetic field-dependent non-local voltages and electromagnetic resonances, bypassing quantum coherence requirements.

Contribution

It introduces two novel experimental techniques to detect Fermi arcs in Weyl semimetals that are more robust than quantum interference effects.

Findings

Non-local DC voltage varies with magnetic field.

Electromagnetic wave transmission shows sharp resonances.

Methods are applicable to Dirac semimetals.

Abstract

Surface Fermi arcs are the most prominent manifestation of the topological nature of Weyl semimetals. In the presence of a static magnetic field oriented perpendicular to the sample surface, their existence leads to unique inter-surface cyclotron orbits. We propose two experiments which directly probe the Fermi arcs: a magnetic field dependent non-local DC voltage and sharp resonances in the transmission of electromagnetic waves at frequencies controlled by the field. We show that these experiments do not rely on quantum mechanical phase coherence, which renders them far more robust and experimentally accessible than quantum effects. We also comment on the applicability of these ideas to Dirac semimetals.