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arXiv · 1606.03614

Femtosecond spin current pulses generated by the non-thermal spin-dependent Seebeck effect and interacting with ferromagnets in spin valves

Alexandr Alekhin·Ilya Razdolski·Nikita Ilin·Jan P. Meyburg·Detlef Diesing·Vladimir Roddatis·Ivan Rungger·Maria Stamenova·Stefano Sanvito·Uwe Bovensiepen·Alexey Melnikov
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Abstract

Using the sensitivity of magneto-induced second harmonic generation to spin currents (SC), we demonstrate in Fe/Au/Fe/MgO(001) pseudo spin valves the generation of 250 fs-long SC pulses. Their temporal profile indicates that superdiffusive hot electron transport across a sub-100~nm Au layer is close to the ballistic limit and the pulse duration is primarily determined by the thermalization time of laser-excited hot carriers in Fe. Considering the calculated spin-dependent Fe/Au interface transmittance we conclude that a non-thermal spin-dependent Seebeck effect is responsible for the generation of ultrashort SC pulses. We also show that hot electron spins rotate upon interaction with non-collinear magnetization at the Au/Fe interface, which holds high potential for future spintronic devices.

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Alexandr Alekhin, Ilya Razdolski, Nikita Ilin, Jan P. Meyburg, Detlef Diesing, Vladimir Roddatis, Ivan Rungger, Maria Stamenova, Stefano Sanvito, Uwe Bovensiepen, Alexey Melnikov. 2016-07-25. Femtosecond spin current pulses generated by the non-thermal spin-dependent Seebeck effect and interacting with ferromagnets in spin valves. https://doi.org/10.1103/physrevlett.119.017202

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