Electronic properties in a quantum well structure of Weyl semimetal

TL;DR

This paper studies how Weyl electrons behave in a quantum well structure, revealing resonant tunneling, angle-dependent transmission, and potential for electron beam collimation in three-dimensional Weyl semimetals.

Contribution

It provides a detailed analysis of confined states and transport properties of Weyl electrons in a quantum well, highlighting unique angle-dependent tunneling and conductance features.

Findings

Confined states exist at specific energies relative to the well and barrier.

Transmission is resonant and angle-sensitive, with perfect transparency at normal incidence.

Conductance can approach zero when Fermi energy aligns with potential edges.

Abstract

We investigate the confined states and transport of three-dimensional Weyl electrons around a one-dimensional external rectangular electrostatic potential. Confined states with finite transverse wave vector exist at energies higher than the half well depth or lower than the half barrier height. The rectangular potential appears completely transparent to normal incident electrons but not otherwise. The tunneling transmission coefficient is sensitive to their incident angle and shows resonant peaks when their energy coincides with the confined spectra. In addition, for electrons in the conduction (valence) band through a potential barrier (well), the transmission spectrum has a gap of width increasing with the incident angle. Interestingly, the electron linear zero-temperature conductance over the potential can approach zero when the Fermi energy is aligned to the top and bottom energies of the potential, when only electron beams normal to the potential interfaces can pass through. The considered structure can be used to collimate Weyl electron beams.