Theory of interedge superexchange in zigzag edge magnetism.

  title={Theory of interedge superexchange in zigzag edge magnetism.},
  author={J. Jung and Tami Pereg-Barnea and Allan H. MacDonald},
  journal={Physical review letters},
  volume={102 22},
A graphene nanoribbon with zigzag edges has a gapped magnetic ground state with an antiferromagnetic interedge superexchange interaction. We present a theory based on asymptotic properties of the Dirac-model ribbon wave function 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… 
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