Strong Modulation of Spin Currents in Bilayer Graphene by Static and Fluctuating Proximity Exchange Fields
| Autor: | Tianyu Liu, Jack Brangham, Jyoti Katoch, Roland Kawakami, Keng-Yuan Meng, Simranjeet Singh, Fengyuan Yang, Tiancong Zhu, Michael E. Flatté |
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| Rok vydání: | 2017 |
| Předmět: |
Condensed Matter - Materials Science
Spin pumping Materials science Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Spin polarization Spintronics Graphene Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences General Physics and Astronomy Spin engineering 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences law.invention Magnetization Ferromagnetism law Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Condensed Matter::Strongly Correlated Electrons 010306 general physics 0210 nano-technology Bilayer graphene |
| Zdroj: | Physical Review Letters. 118 |
| ISSN: | 1079-7114 0031-9007 |
| Popis: | Two dimensional (2D) materials provide a unique platform to explore the full potential of magnetic proximity driven phenomena, which can be further used for applications in next generation spintronic devices. Of particular interest is to understand and control spin currents in graphene by the magnetic exchange field of a nearby ferromagnetic material in graphene/ferromagnetic-insulator (FMI) heterostructures. Here, we present the experimental study showing the strong modulation of spin currents in graphene layers by controlling the direction of the exchange field due to FMI magnetization. Owing to clean interfaces, a strong magnetic exchange coupling leads to the experimental observation of complete spin modulation at low externally applied magnetic fields in short graphene channels. Additionally, we discover that the graphene spin current can be fully dephased by randomly fluctuating exchange fields. This is manifested as an unusually strong temperature dependence of the non-local spin signals in graphene, which is due to spin relaxation by thermally-induced transverse fluctuations of the FMI magnetization. |
| Databáze: | OpenAIRE |
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