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arXiv · 1504.01591

Spin Transport in Hydrogenated Graphene

David Soriano·Dinh Van Tuan·Simon M. -M. Dubois·Martin Gmitra·Aron W. Cummings·Denis Kochan·Frank Ortmann·Jean-Christophe Charlier·Jaroslav Fabian·Stephan Roche
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Abstract

In this review we discuss the multifaceted problem of spin transport in hydrogenated graphene from a theoretical perspective. The current experimental findings suggest that hydrogenation can either increase or decrease spin lifetimes, which calls for clarification. We first discuss the spin-orbit coupling induced by local $σ-π$ re-hybridization and ${\bf sp}^{3}$ C-H defect formation together with the formation of a local magnetic moment. First-principles calculations of hydrogenated graphene unravel the strong interplay of spin-orbit and exchange couplings. The concept of magnetic scattering resonances, recently introduced \cite{Kochan2014} is revisited by describing the local magnetism through the self-consistent Hubbard model in the mean field approximation in the dilute limit, while spin relaxation lengths and transport times are computed using an efficient real space order N wavepacket propagation method. Typical spin lifetimes on the order of 1 nanosecond are obtained for 1 ppm of hydrogen impurities (corresponding to transport time about 50 ps), and the scaling of spin lifetimes with impurity density is described by the Elliott-Yafet mechanism. This reinforces the statement that magnetism is the origin of the substantial spin polarization loss in the ultraclean graphene limit.

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David Soriano, Dinh Van Tuan, Simon M. -M. Dubois, Martin Gmitra, Aron W. Cummings, Denis Kochan, Frank Ortmann, Jean-Christophe Charlier, Jaroslav Fabian, Stephan Roche. 2015-04-07. Spin Transport in Hydrogenated Graphene. https://doi.org/10.1088/2053-1583%2F2%2F2%2F022002

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