Magnetism-Dependent Transport Phenomena in Hydrogenated Graphene: From Spin-Splitting to Localization Effects

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• 作者：Nicolas Leconte ; David Soriano ; Stephan Roche ; Pablo Ordejon ; Jean-Christophe Charlier ; J. J. Palacios
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：May 24, 2011
• 年：2011
• 卷：5
• 期：5
• 页码：3987-3992
• 全文大小：1045K
• 年卷期：0
• ISSN：1936-086X

文摘

Spin-dependent transport in hydrogenated two-dimensional graphene is explored theoretically. Adsorbed atomic hydrogen impurities can either induce a local antiferromagnetic, ferromagnetic, or nonmagnetic state depending on their density and relative distribution. To describe the various magnetic possibilities of hydrogenated graphene, a self-consistent Hubbard Hamiltonian, optimized by ab initio calculations, is first solved in the mean field approximation for small graphene cells. Then, an efficient order N Kubo transport methodology is implemented, enabling large scale simulations of functionalized graphene. Depending on the underlying intrinsic magnetic ordering of hydrogen-induced spins, remarkably different transport features are predicted for the same impurity concentration. Indeed, while the disordered nonmagnetic graphene system exhibits a transition from diffusive to localization regimes, the intrinsic ferromagnetic state exhibits unprecedented robustness toward quantum interference, maintaining, for certain resonant energies, a quasiballistic regime up to the micrometer scale. Consequently, low temperature transport measurements could unveil the presence of a magnetic state in weakly hydrogenated graphene.