Klein tunneling in deformed honeycomb-dice lattice: from massless to massive particles

Abstract

We show that under compressive uniaxial deformation of the three-band $\alpha -T_3$ lattice, the Dirac cones move toward each other, merge, and a gap opens, while the flat band remains unchanged. Consequently, the low-energy spectrum transitions from linear to quadratic dispersion, indicating the shift from massless to massive Dirac particles. Here, we theoretically investigate the tunneling properties of particles through a sharp $np$ junction in a deformed $\alpha -T_3$ lattice, focusing on the case where the particle energy is half the junction height. We show that this transition from massless to massive particles leads to a change from omnidirectional total transmission, known as super-Klein tunneling, to omnidirectional total reflection, referred to as anti-super-Klein tunneling, in the case of the dice lattice ($\alpha =1$). For all values of $\alpha$, this transition manifests as a change from conventional Klein tunneling to anti-Klein tunneling.

15 pages, 7 figures

References in corpus (13)

• Electric Field Effect in Atomically Thin Carbon Films
• Chiral tunneling and the Klein paradox in graphene
• A tight-binding approach to uniaxial strain in graphene
• Quantum interference and Klein tunneling in graphene heterojunctions
• Evidence of Klein tunneling in graphene p-n junctions
• Transport measurements across a tunable potential barrier in graphene
• Merging of Dirac points in a two-dimensional crystal
• Valleytronics in merging Dirac cones: All-electric-controlled valley filter, valve and universal reversible logic gate
• Magneto-optics of massless Kane fermions: Role of the flat band and unusual Berry phase
• Floquet topological phase transition in $\alpha$-${\mathcal{T}}_3$ lattice
• Dynamical Floquet spectrum of Kekulé-distorted graphene under normal incidence of electromagnetic radiation
• Dynamical optical conductivity for gapped $\alpha -{\mathcal{T}}_3$ materials with a curved "flat" band
• Magnetic Fabry-Pérot interferometer for valley filtering in a honeycomb-dice model