First Principles Study of Magnetism Induced by Topological Frustration of Bowtie-Shaped Graphene Nanoflake

Fine-tuning magnetic states by understanding topological frustration inducing magnetic mechanism should allow greater flexibility for the design of graphene-based spintronics. Based on first-principles calculations, it is predicted that bowtie-shaped graphene nanoflake (GNF) is of spin-polarized ground state exhibiting antiferromagnetic (AFM) ordering between two individual triangular GNFs. It is demonstrated that strength of antiferromagnetic coupling of both symmetric and asymmetric bowtie-shaped GNF displays strong zero-energy-state-orientated behavior due to non-trivial nature of topological frustration, with implications for designing graphene nanostructures with predefined magnetic states. It also proposes a specific example of structures that can serve as nanoscale molecular logic gates composed by asymmetric bowtie-shaped GNFs units, which augment the special antiferromagnetic function through structural configuration of multi-bowtie-shaped GNFs.