Effective Zeeman splitting in bent lateral heterojunctions of graphene and hexagonal boron nitride: A new mechanism towards half-metallicity

Abstract

Low-dimensional half-metallic (HM) systems are invaluable for future spintronics. Yet a definitive experimental demonstration of HM characteristic in two-dimensional (2D) materials remains elusive. Here, we reveal that in recently synthesized graphene/hexagonal boron nitride ($\mathrm{G}\text{/}h\mathrm{BN}$) lateral heterojunctions, pronounced HM can be achieved by applying an in-plane bending. We demonstrate with generalized Bloch theorem that bending has strong influence on interfacial spin states, mimicking the Zeeman effect, which consequently leads to the desired HM phase with a sizable HM gap and excellent magnetic stability. Given recent experimental advances in fabrication of $\mathrm{G}\text{/}h\mathrm{BN}$ heterostructures, this strain-driven HM phase may be practically accessible. The generalized Bloch theorem coupled with self-consistent charge density-functional tight binding is useful to model 2D structures under fundamental deformations, thus may boost the study of strain tunable electronic property of low-dimensional materials with inhomogeneous strain patterns.