Terahertz Spin-to-Charge Current Conversion in Stacks of Ferromagnets and the Transition-Metal Dichalcogenide NbSe2

Nadvornik L, Gueckstock O, Braun L, Niu C, Graefe J, Richter G, Schuetz G, Takagi H, Zeer M, Seifert TS, Kubascik P, Pandeya AK, Anane A, Yang H, Bedoya-Pinto A, Parkin SSP, Wolf M, Mokrousov Y, Nakamura H, Kampfrath T (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Advanced Materials Interfaces WILEY-VCH Verlag GmbH & Co. KGaA

Book Volume: 9

Article Number: 2201675

Journal Issue: 36

DOI: 10.1002/admi.202201675

Abstract

Transition-metal dichalcogenides (TMDCs) are an aspiring class of materials with unique electronic and optical properties and potential applications in spin-based electronics. Here, terahertz emission spectroscopy is used to study spin-to-charge current conversion (S2C) in the TMDC NbSe2 in ultra-high-vacuum-grown F|NbSe2 thin-film stacks, where F is a layer of ferromagnetic Fe or Ni. Ultrafast laser excitation triggers an ultrafast spin current that is converted into an in-plane charge current and, thus, a measurable THz electromagnetic pulse. The THz signal amplitude as a function of the NbSe2 thickness shows that the measured signals are fully consistent with an ultrafast optically driven injection of an in-plane-polarized spin current into NbSe2. Modeling of the spin-current dynamics reveals that a sizable fraction of the total S2C originates from the bulk of NbSe2 with the opposite, negative sign of the spin Hall angle as compared to Pt. By a quantitative comparison of the emitted THz radiation from F|NbSe2 to F|Pt reference samples and the results of ab initio calculations, it is estimated that the spin Hall angle of NbSe2 for an in-plane polarized spin current lies between -0.2% and -1.1%, while the THz spin-current relaxation length is of the order of a few nanometers.

Involved external institutions

Max-Planck-Institut für Festkörperforschung DE Germany (DE) Forschungszentrum Jülich / Research Centre Jülich (FZJ) DE Germany (DE) Freie Universität Berlin DE Germany (DE) Univerzita Karlova v Praze / Charles University in Prague CZ Czech Republic (CZ) Max-Planck-Institut für Mikrostrukturphysik (MSP) / Max Planck Institute for Microstructure Physics DE Germany (DE) École Polytechnique - Université Paris-Saclay FR France (FR) Korea Advanced Institute of Science and Technology (KAIST) KR Korea, Republic of (KR) Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI) DE Germany (DE)

How to cite

APA:

Nadvornik, L., Gueckstock, O., Braun, L., Niu, C., Graefe, J., Richter, G.,... Kampfrath, T. (2022). Terahertz Spin-to-Charge Current Conversion in Stacks of Ferromagnets and the Transition-Metal Dichalcogenide NbSe2. Advanced Materials Interfaces, 9(36). https://dx.doi.org/10.1002/admi.202201675

MLA:

Nadvornik, Lukas, et al. "Terahertz Spin-to-Charge Current Conversion in Stacks of Ferromagnets and the Transition-Metal Dichalcogenide NbSe2." Advanced Materials Interfaces 9.36 (2022).

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