Asymmetric quantum confinement-induced energetically and spatially splitting Dirac rings in graphene/phosphorene/graphene heterostructure

Abstract

Graphene-based two dimensional atomically thin van der Waals heterostructures show peculiar electronic feature such as energetically resolved Dirac ring. Using first-principles calculations, here we observe that there are two splitting Dirac cones in graphene/phosphorene/graphene trilayer heterostructure, which have not only the relatively large band gap opening as usual, but also possess both distinctly spatially and energetically resolved property. The underling mechanism can be attributed to the asymmetric quantum confinement-induced asymmetric charge distribution due to the presence of glide reflection of phosphorene, leading to different coupling strength between the two layers of graphene and phosphorene. As a result, the induced resolved Dirac rings have substantially different Dirac features such as Fermi velocity and asymmetric factor. Such unique features are absence in phosphorene/graphene bilayer heterostructure and the counterpart crystal. These findings provide new insights into the Dirac electric properties, and can be useful for future design of graphene-based trilayer heterostructure. (C) 2018 Elsevier Ltd. All rights reserved.