Inhomogeneous strain-induced half-metallicity in bent zigzag graphene nanoribbons

Abstract

Half-metallicity: Strain-induced spin-splitting in graphene nanoribbons Inhomogenous strain could cause the charge carriers in zigzag graphene nanoribbons to become fully spin-polarized. If a material is conducting for one spin orientation, whilst being insulating for the other, then it is said to be half-metallic. Such materials could be used in a range of spintronic applications; whilst half-metallicity has been seen in bulk systems, realising half-metallicity in low-dimensional materials is challenging. Using the theoretical method of generalized Bloch theorem, Dong-Bo Zhang and Su-Huai Wei from Beijing Computational Science Research Center show that in-plane bending can be used to induce half-metallicity in zigzag graphene nanoribbons. When graphene nanoribbons are bent, inhomogenous strains are created that lead to a spin-splitting of the electronic states, which gives rise to half-metallicity. This strain engineering approach could be extended to other two-dimensional materials, enabling the design of nanoscale spintronics devices.