It is proposed that the observed small (100 ps) spin relaxation time in graphene is due to resonant scattering by local magnetic moments. At resonances, magnetic moments behave as spin hot spots: the spin-flip scattering rates are as large as the spin-conserving ones, as long as the exchange interaction is greater than the resonance width. Smearing of the resonance peaks by the presence of electron-hole puddles gives quantitative agreement with experiment, for about 1 ppm of local moments. While the local moments can come from a variety of sources, we specifically focus on hydrogen adatoms. We perform first-principles supercell calculations and introduce an effective Hamiltonian to obtain realistic input parameters for our mechanism.
@article{arxiv.1306.0230,
title = {Spin relaxation mechanism in graphene: resonant scattering by magnetic impurities},
author = {Denis Kochan and Martin Gmitra and Jaroslav Fabian},
journal= {arXiv preprint arXiv:1306.0230},
year = {2014}
}