First-principles study of magnetism development in armchair graphene nanoribbons with edge functionalizations

Abstract

Graphene nanoribbons with zigzag-shaped edge (zGNRs) are predicted to be magnetic insulator at the ground state, attracting significant interest in view of spintronic applications. On the other hand, although they are energetically and thermodynamically more favored than zGNRs, graphene nanoribbons with armchair-shaped edge (aGNRs) have been less spotlighted than zGNRs due to the absence of magnetism. In recent years, atomically controllable bottom-up synthesis technologies of functionalized aGNRs have been actively studied and developed. Herein, based on the combined density functional theory (DFT) and matrix Green's function (MGF) approach, we consider aGNRs functionalized with various functional groups or edge shapes, and show that the spin polarizations develop for some of the considered functionalization cases. The origin of the induced magnetism will be discussed within the Lieb’s theorem. This work will provide a novel guidance for the development of graphene-based spintronic devices.