title: Theory of interedge superexchange in zigzag edge magnetism.
abstract: 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 favored by both kinetic and interaction energies.
authors: Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA. jeil@physics.utexas.edu
authors: J
authors: J
authors: Jung
authors: T
authors: T
authors: Pereg-Barnea
authors: A H
authors: AH
authors: Macdonald