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arXiv · 1805.02193

Terahertz spectroscopy for all-optical spintronic characterization of the spin-Hall-effect metals Pt, W and Cu$_{80}$Ir$_{20}$

Tom Sebastian Seifert·Ngoc Minh Tran·Oliver Gueckstock·Seyed Mohammedreza Rouzegar·Lukas Nadvornik·Samridh Jaiswal·Gerhard Jakob·Vasily V. Temnov·Markus Muenzenberg·Martin Wolf·Mathias Klaeui·Tobias Kampfrath
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Abstract

Identifying materials with an efficient spin-to-charge conversion is crucial for future spintronic applications. The spin Hall effect is a central mechanism as it allows for the interconversion of spin and charge currents. Spintronic material research aims at maximizing its efficiency, quantified by the spin Hall angle $\Theta_{\textrm{SH}}$ and the spin-current relaxation length $\lambda_{\textrm{rel}}$. We develop an all-optical method with large sample throughput that allows us to extract $\Theta_{\textrm{SH}}$ and $\lambda_{\textrm{rel}}$. Employing terahertz spectroscopy, we characterize magnetic metallic heterostructures involving Pt, W and Cu$_{80}$Ir$_{20}$ in terms of their optical and spintronic properties. We furthermore find indications that the interface plays a minor role for the spin-current transmission. Our analytical model is validated by the good agreement with literature DC values. These findings establish terahertz emission spectroscopy as a reliable tool complementing the spintronics workbench.

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Tom Sebastian Seifert, Ngoc Minh Tran, Oliver Gueckstock, Seyed Mohammedreza Rouzegar, Lukas Nadvornik, Samridh Jaiswal, Gerhard Jakob, Vasily V. Temnov, Markus Muenzenberg, Martin Wolf, Mathias Klaeui, Tobias Kampfrath. 2018-05-06. Terahertz spectroscopy for all-optical spintronic characterization of the spin-Hall-effect metals Pt, W and Cu$_{80}$Ir$_{20}$. https://doi.org/10.1088/1361-6463/aad536

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