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arXiv · 0711.0207

Magnetic Correlations at Graphene Edges

Oleg V. Yazyev·M. I. Katsnelson
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Abstract

Magnetic zigzag edges of graphene are considered as a basis for novel spintronics devices despite the fact that no true long-range magnetic order is possible in one dimension. We study the transverse and longitudinal fluctuations of magnetic moments at zigzag edges of graphene from first principles. We find a high value for the spin wave stiffness $D$ = 2100 meV Å$^2$ and a spin-collinear domain wall creation energy $E_dw$ = 114 meV accompanied by low magnetic anisotropy. Above the crossover temperature $T_x \approx$10 K the spin correlation length $ξ\propto T^{-1}$ limits the long-range magnetic order to ~1 nm at 300 K while below $T_x$ it grows exponentially with decreasing temperature. We discuss possible ways of increasing the range of magnetic order and effects of edge roughness on it.

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Oleg V. Yazyev, M. I. Katsnelson. 2007-11-01. Magnetic Correlations at Graphene Edges. https://doi.org/10.1103/physrevlett.100.047209

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