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arXiv · 2102.05390

Imprinting Tunable ${\pi}$-Magnetism in Graphene Nanoribbons via Edge Extensions

Michele Pizzochero·Efthimios Kaxiras
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Abstract

Magnetic carbon nanostructures are currently under scrutiny for a wide spectrum of applications. Here, we theoretically investigate armchair graphene nanoribbons patterned with asymmetric edge extensions consisting of laterally fused naphtho groups, as recently fabricated via on-surface synthesis. We show that an individual edge extension acts as a spin-$\frac{1}{2}$ center and develops a sizable spin-polarization of the conductance around the band edges. The Heisenberg exchange coupling between a pair of edge extensions is dictated by the position of the second naphtho group in the carbon backbone, thus enabling ferromagnetic, antiferromagnetic, or non-magnetic states. The periodic arrangement of edge extensions yields full spin-polarization at the band extrema, and the accompanying ferromagnetic ground state can be driven into non-magnetic or antiferromagnetic phases through external stimuli. Overall, our work reveals precise tunability of the ${\pi}$-magnetism in graphene nanoribbons induced by naphtho groups, thereby establishing these one-dimensional architectures as suitable platforms for logic spintronics.

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Michele Pizzochero, Efthimios Kaxiras. 2021-02-10. Imprinting Tunable ${\pi}$-Magnetism in Graphene Nanoribbons via Edge Extensions. https://doi.org/10.1021/acs.jpclett.0c03677

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