Barrier transmission of Dirac-like pseudospin-one particles

TL;DR

This paper investigates barrier tunneling in a two-dimensional dice lattice with Dirac-like pseudospin-one particles, revealing enhanced Klein tunneling and magnetic barrier effects, confirmed through numerical and semiclassical analyses.

Contribution

It introduces the study of barrier transmission for pseudospin-one particles in a dice lattice, extending the understanding beyond graphene's pseudospin-half systems.

Findings

Enhanced super Klein tunneling in the dice lattice.

Magnetic barriers can confine particles via semiclassical orbits.

Landau levels are characterized for the system.

Abstract

We address the problem of barrier tunneling in the two-dimensional T_3 lattice (dice lattice). In particular we focus on the low-energy, long-wavelength approximation for the Hamiltonian of the system, where the lattice can be described by a Dirac-like Hamiltonian associated with a pseudospin one. The enlarged pseudospin S = 1 (instead of S = 1/2 as for graphene) leads to an enhanced "super" Klein tunneling through rectangular electrostatic barriers. Our results are confirmed via numerical investigation of the tight-binding model of the lattice. For a uniform magnetic field, we discuss the Landau levels and we investigate the transparency of a rectangular magnetic barrier. We show that the latter can mainly be described by semiclassical orbits bending the particle trajectories, qualitatively similar as it is the case for graphene. This makes it possible to confine particles with magnetic barriers of sufficient width.