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| Principais autores: | , , , , , , , , , |
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| Formato: | Preprint |
| Publicado em: |
2015
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| Acesso em linha: | https://arxiv.org/abs/1504.01591 |
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| _version_ | 1866912413226369024 |
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| author | Soriano, David Van Tuan, Dinh Dubois, Simon M. -M. Gmitra, Martin Cummings, Aron W. Kochan, Denis Ortmann, Frank Charlier, Jean-Christophe Fabian, Jaroslav Roche, Stephan |
| author_facet | Soriano, David Van Tuan, Dinh Dubois, Simon M. -M. Gmitra, Martin Cummings, Aron W. Kochan, Denis Ortmann, Frank Charlier, Jean-Christophe Fabian, Jaroslav Roche, Stephan |
| contents | 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. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_1504_01591 |
| institution | arXiv |
| publishDate | 2015 |
| record_format | arxiv |
| spellingShingle | Spin Transport in Hydrogenated Graphene Soriano, David Van Tuan, Dinh Dubois, Simon M. -M. Gmitra, Martin Cummings, Aron W. Kochan, Denis Ortmann, Frank Charlier, Jean-Christophe Fabian, Jaroslav Roche, Stephan Mesoscale and Nanoscale Physics 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. |
| title | Spin Transport in Hydrogenated Graphene |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/1504.01591 |