Spin state engineering of triangulene graphene embedded in h-BN nanoflake

Abstract

Zigzag-edged graphene nanoislands hold great potential in nanoelectronics and spintronics applications, however, controlling its edge chemistry is still challenging from the experimental perspective. One promising strategy to circumvent the issues associated with the highly reactive graphene zigzag edges is to incorporate it into an insulator matrix (e.g., hexagonal boron nitride). In light of this, stability, electronic and magnetic properties of hybrid graphene/BN nanoflakes are investigated through the Density functional theory (DFT). The results reveal that the formation of separated graphene and h-BN domains would be feasible in hybrid flakes. The multiplicity of the finite heterostructures is dictated by the carbon domain, regardless the position, size, and whether the carbon islands are connected or not. To investigate the feasibility of spin state engineering, changes in the highest orbital occupations were evaluated by increasing the applied electric or magnetic field magnitude. The results indicate that an external electric field above a critical value can induce a degeneracy of ground and first excited spin state, which might pave the way for a spin state transition triggered by a magnetic field perturbation.