The energy scale of Dirac electrons in Cd3As2

TL;DR

This study uses Landau level spectroscopy to estimate the energy scale of 3D Dirac electrons in Cd3As2, revealing that their presence is confined to energies below 40 meV, contrary to previous beliefs.

Contribution

It provides the first experimental estimate of the energy scale of Dirac electrons in Cd3As2 using Landau level spectroscopy.

Findings

Dirac electrons in Cd3As2 are confined below 40 meV

Landau level spectroscopy effectively probes Dirac band structure

Challenges previous assumptions about the energy extent of Dirac states

Abstract

Cadmium arsenide (Cd3As2) has recently became conspicuous in solid-state physics due to several reports proposing that it hosts a pair of symmetry-protected 3D Dirac cones. Despite vast investigations, a solid experimental insight into the band structure of this material is still missing. Here we fill one of the existing gaps in our understanding of Cd3As2, and based on our Landau level spectroscopy study, we provide an estimate for the energy scale of 3D Dirac electrons in this system. We find that the appearance of such charge carriers is limited - contrary to a widespread belief in the solid-state community - to a relatively small energy scale (below 40 meV).