Dirac spectrum in gated multilayer black phosphorus nanoribbons

TL;DR

This paper studies how applying a perpendicular electric field to multilayer black phosphorus nanoribbons induces a transition to Dirac-like spectra, affecting their electronic properties and offering a way to determine physical characteristics.

Contribution

It reveals the conditions for Dirac spectrum emergence in gated multilayer phosphorene nanoribbons and links this transition to their physical and electronic properties.

Findings

Dirac-like spectra appear when gate density exceeds a critical value

Screening effects influence the critical gate density

Transition impacts electronic transport properties

Abstract

We investigate the effects of a perpendicular electric field applied to multilayer phosphorene nanoribbons with zigzag and armchair edges. Within the context of the tight-binding model, we explore the electronic properties of these systems giving emphasis to the appearance of Dirac-like spectra, a transition that occurs when the gate density associated with the applied displacement field is greater than the critical value $n_c$. We show that the confinement properties and the screening effects in such systems play an important role on the determination of $n_c$, suggesting a scheme to determine the thickness, width and edge orientation of multilayered phosphorene nanoribbons. We also explore how this transition affects the electronic transport properties of such systems.