Magnetic Correlations at Graphene Edges: Basis for Novel Spintronics Devices

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 $D=2100\text{ }\text{ }\mathrm{meV}\text{ }{\AA{}}^{2}$ and a spin-collinear domain wall creation energy ${E}_{\mathrm{dw}}=114\text{ }\text{ }\mathrm{meV}$ accompanied by low magnetic anisotropy. Above the crossover temperature ${T}_{x}\ensuremath{\approx}10\text{ }\text{ }\mathrm{K}$, the spin correlation length…