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arXiv · 2310.12082

Accessing ultrafast spin-transport dynamics in copper using broadband terahertz spectroscopy

Jiří Jechumtál·Reza Rouzegar·Oliver Gueckstock·Christian Denker·Wolfgang Hoppe·Quentin Remy·Tom S. Seifert·Peter Kubaščík·Georg Woltersdorf·Piet W. Brouwer·Markus Münzenberg·Tobias Kampfrath·Lukáš Nádvorník
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Abstract

We study the spatiotemporal dynamics of ultrafast electron spin transport across nanometer-thick copper layers using broadband terahertz spectroscopy. Our analysis of temporal delays, broadening and attenuation of the spin-current pulse revealed ballistic-like propagation of the pulse peak, approaching the Fermi velocity, and diffusive features including a significant velocity dispersion. A comparison to the frequency-dependent Ficks law identified the diffusion-dominated transport regime for distances larger than 2 nm. The findings lie the groundwork for designing future broadband spintronic devices.

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Jiří Jechumtál, Reza Rouzegar, Oliver Gueckstock, Christian Denker, Wolfgang Hoppe, Quentin Remy, Tom S. Seifert, Peter Kubaščík, Georg Woltersdorf, Piet W. Brouwer, Markus Münzenberg, Tobias Kampfrath, Lukáš Nádvorník. 2023-10-18. Accessing ultrafast spin-transport dynamics in copper using broadband terahertz spectroscopy. https://doi.org/10.1103/physrevlett.132.226703

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