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arXiv · 0812.1047

Theory of inter-edge superexchange in zigzag edge magnetism

J. Jung·T. Pereg-Barnea·A. H. MacDonald
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Abstract

A graphene nanoribbon with zigzag edges has a gapped magnetic ground state with an antiferromagnetic inter-edge superexchange interaction. We present a theory based on asymptotic properties of the Dirac-model ribbon wavefunction which predicts $W^{-2}$ and $W^{-1}$ ribbon-width dependencies for the superexchange interaction strength and the charge gap respectively. We find that, unlike the case of conventional atomic scale superexchange, opposite spin-orientations on opposite edges of the ribbon are favored by both kinetic and interaction energies.

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J. Jung, T. Pereg-Barnea, A. H. MacDonald. 2008-12-04. Theory of inter-edge superexchange in zigzag edge magnetism. https://doi.org/10.1103/physrevlett.102.227205

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