Electron interactions and Dirac fermions in graphene-Ge2Sb2Te5 superlattices

Graphene based superlattices have been attracted worldwide interest due to the combined properties of the graphene Dirac cone feature and all kinds of advanced functional materials. In this work, we proposed a novel series of graphene-Ge2Sb2Te5 superlattices based on the density functional theory calculations. We demonstrated the stability in terms of energy and lattice dynamics for such kind of artificial materials. The analysis of the electronic structures unravels the gap opening nature at Dirac cone of the insert graphene layer. The Dirac fermions in the graphene layers are strongly affected by the electron spin orbital coupling in the Ge2Sb2Te5 layers. The present results show the possible application in phase-change data storage of such kind of superlattice materials, where the Ge2Sb2Te5 layers exhibit as the phase-change data storage media and the graphene layer works as the electrode, probe, and heat conductor. (C) 2014 AIP Publishing LLC.