Length Scale of the Spin Seebeck Effect
Autor: | Er-Jia Guo, Andreas Kehlberger, Mehmet C. Onbasli, Gerhard Jakob, Ulrike Ritzmann, Burkard Hillebrands, Caroline A. Ross, Ulrich Nowak, Matthias B. Jungfleisch, Mathias Kläui, Dong-Hun Kim, Denise Hinzke, Joel Cramer |
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Rok vydání: | 2015 |
Předmět: |
Length scale
Materials science Condensed matter physics Spin polarization Magnon Yttrium iron garnet General Physics and Astronomy pacs:72.25.-b Condensed Matter::Materials Science chemistry.chemical_compound chemistry pacs:72.20.Pa pacs:75.40.Gb Spin wave Ferrimagnetism Thermoelectric effect ddc:530 Condensed Matter::Strongly Correlated Electrons pacs:75.30.Ds Spin-½ |
Zdroj: | Physical Review Letters. 115 |
ISSN: | 1079-7114 0031-9007 |
Popis: | We investigate the origin of the spin Seebeck effect in yttrium iron garnet (YIG) samples for film thicknesses from 20 nm to 50 μm at room temperature and 50 K. Our results reveal a characteristic increase of the longitudinal spin Seebeck effect amplitude with the thickness of the insulating ferrimagnetic YIG, which levels off at a critical thickness that increases with decreasing temperature. The observed behavior cannot be explained as an interface effect or by variations of the material parameters. Comparison to numerical simulations of thermal magnonic spin currents yields qualitative agreement for the thickness dependence resulting from the finite magnon propagation length. This allows us to trace the origin of the observed signals to genuine bulk magnonic spin currents due to the spin Seebeck effect ruling out an interface origin and allowing us to gauge the reach of thermally excited magnons in this system for different temperatures. At low temperature, even quantitative agreement with the simulations is found. |
Databáze: | OpenAIRE |
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