Transport properties of the pseudospin-3/2 Dirac-Weyl fermions in the double-barrier-modulated two-dimensional system

TL;DR

This paper analytically investigates the transport properties of pseudospin-3/2 Dirac-Weyl fermions in a double-barrier two-dimensional system, revealing unique tunneling effects and enhanced conductivity compared to lower pseudospin systems.

Contribution

It provides an analytical solution for the pseudospin-3/2 Dirac equation and explores its transport phenomena, including tunneling effects and conductance, in a double-barrier modulated system.

Findings

Klein and resonant tunneling observed in pseudospin-3/2 system

Enhanced conductivity and shot noise compared to pseudospin-1/2 and 1 systems

Fano factor between 0.4 and 0.5 near the Dirac point

Abstract

In this work, we analytically solved the pseudospin-3/2 Dirac equation and investigated the electronic transport properties in the double-barrier modulated two-dimensional system. The probability current density operator is explicitly derived from the time-dependent pseudospin-3/2 Dirac equation, which paves way for investigation of the electronic transport properties of general pseudospin-$s$ Dirac-Weyl systems with $s$ an integer or half integer larger than 1. As a result of the double-cone band structure, the pseudospin-3/2 system has two incident channels for a single incident energy and incident angle pair. Similar to its counterparts of pseudospin-1/2 and pseudospin-1 Dirac-Weyl systems, the Klein tunneling and resonant tunneling effects in the transmission probability are numerically observed for incidence coming from both Dirac cones in the double-barrier-modulated pseudospin-3/2 system. In contrast to its pseudospin-1/2 and -1 counterparts, the Klein tunneling and resonant tunneling effects are differentiated into double-channel and single-channel incidences, corresponding to different regimes in the $E$-$k_y$ dispersion plane. Without a flat band, the super Klein tunneling effect of the pseudospin-1 Dirac-Weyl system does not occur in the pseudospin-3/2 system. Using the numerically obtained probability current density, the zero-temperature conductivity, shot noise, and Fano factor are calculated. As a combined result of double-channel incidence, Klein tunneling, and resonant tunneling, in comparison with its pseudospin-1/2 (graphene) and pseudospin-1 counterparts, the conductivity and shot noise in the pseudospin-3/2 double-barrier structure is enhanced. A Fano factor between 0.4 and 0.5 close to the Dirac point ${E_F}={V_0}$ is observed.