0000000001107890

AUTHOR

Shun Watanabe

showing 2 related works from this author

Tuning Spin Current Injection at Ferromagnet-Nonmagnet Interfaces by Molecular Design.

2020

There is a growing interest in utilizing the distinctive material properties of organic semiconductors for spintronic applications. Here, we explore the injection of pure spin current from Permalloy into a small molecule system based on dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophene (DNTT) at ferromagnetic resonance. The unique tunability of organic materials by molecular design allows us to study the impact of interfacial properties on the spin injection efficiency systematically. We show that both the spin injection efficiency at the interface and the spin diffusion length can be tuned sensitively by the interfacial molecular structure and side chain substitution of the molecule.

PermalloyMaterials scienceSpintronicsCondensed matter physicsPhysiqueSpin injectionFOS: Physical sciencesGeneral Physics and AstronomyApplied Physics (physics.app-ph)Physics - Applied PhysicsSpintronics01 natural sciencesFerromagnetic resonanceOrganic semiconductorFerromagnetismOrganic semiconductors0103 physical sciencesSpin diffusionSide chainMolecule010306 general physicsFerromagnetsSpin pumpingPhysical review letters
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Femtosecond formation dynamics of the spin Seebeck effect revealed by terahertz spectroscopy

2018

Understanding the transfer of spin angular momentum is essential in modern magnetism research. A model case is the generation of magnons in magnetic insulators by heating an adjacent metal film. Here, we reveal the initial steps of this spin Seebeck effect with <27fs time resolution using terahertz spectroscopy on bilayers of ferrimagnetic yttrium-iron garnet and platinum. Upon exciting the metal with an infrared laser pulse, a spin Seebeck current $j_\textrm{s}$ arises on the same ~100fs time scale on which the metal electrons thermalize. This observation highlights that efficient spin transfer critically relies on carrier multiplication and is driven by conduction electrons scattering …

MagnetismTerahertz radiation0299 Other Physical SciencesScienceGeneral Physics and AstronomyFOS: Physical sciencesPhysics::Optics02 engineering and technology01 natural sciencesGeneral Biochemistry Genetics and Molecular BiologyArticleCondensed Matter::Materials ScienceFerrimagnetism5370103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)ddc:530010306 general physicsSpin (physics)lcsh:ScienceTerahertz opticsPhysicsSpin pumpingCondensed Matter - Materials ScienceMultidisciplinaryCondensed matter physicsCondensed Matter - Mesoscale and Nanoscale PhysicsMagnonFar-infrared laserQMaterials Science (cond-mat.mtrl-sci)General ChemistrySpintronics021001 nanoscience & nanotechnology3. Good healthTerahertz spectroscopy and technologylcsh:QCondensed Matter::Strongly Correlated Electrons0210 nano-technology
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