Spin-orbit interaction driven terahertz nonlinear dynamics in transition metals
The interplay of electronic charge, spin, and orbital currents, coherently driven by picosecond long oscillations of light fields in spin-orbit coupled systems, is the foundation of emerging terahertz lightwave spintronics and orbitronics. The essential rules for how terahertz fields interact with these systems in a nonlinear way are still not understood. In this work, we demonstrate a universally applicable electronic nonlinearity originating from spin-orbit interactions in conducting materials, wherein the interplay of light-induced spin and orbital textures manifests. We utilized terahertz harmonic generation spectroscopy to investigate the nonlinear dynamics over picosecond timescales in various transition metal films. We found that the terahertz harmonic generation efficiency scales with the spin Hall conductivity in the studied films, while the phase takes two possible values (shifted by π), depending on the <i>d</i>-shell filling. These findings elucidate the fundamental mechanisms governing non-equilibrium spin and orbital polarization dynamics at terahertz frequencies, which is relevant for potential applications of terahertz spin- and orbital-based devices.
Authors
- Carmine Ortix (ORCID: https://orcid.org/0000-0002-6334-0569)
- Markus Lysne
- Igor Ilyakov (ORCID: https://orcid.org/0000-0002-5928-7996)
- Michael Schüler (ORCID: https://orcid.org/0000-0001-7322-6367)
- J. Lindner (ORCID: https://orcid.org/0000-0002-4955-515X)
- Pavlo Makushko (ORCID: https://orcid.org/0000-0003-2693-1180)
- Denys Makarov (ORCID: https://orcid.org/0000-0002-7177-4308)
- Alexey Ponomaryov (ORCID: https://orcid.org/0000-0003-1200-2866)
- Thales V. A. G. de Oliveira (ORCID: https://orcid.org/0000-0002-4886-0654)
- Gulloo Lal Prajapati (ORCID: https://orcid.org/0000-0001-7111-4206)
- T. E. Cowan (ORCID: https://orcid.org/0000-0002-5845-000X)
- J. Faßbender (ORCID: https://orcid.org/0000-0003-3893-9630)
- Aleksandra Lindner
- Ruslan Salikhov (ORCID: https://orcid.org/0000-0001-8461-0743)
- Atiqa Arshad (ORCID: https://orcid.org/0000-0002-5142-5565)
- Philipp Werner (ORCID: https://orcid.org/0000-0002-2136-6568)
- Jan‐Christoph Deinert (ORCID: https://orcid.org/0000-0001-6211-0158)
- Sergey Kovalev (ORCID: https://orcid.org/0000-0002-2290-1016)
Institutions
- University of Salerno (IT)
- University of Fribourg (CH)
- TU Dortmund University (DE)
- Helmholtz-Zentrum Dresden-Rossendorf (DE)
- Paul Scherrer Institute (CH)
- Technische Universität Dresden (DE)
Publication Details
- Journal
- npj Spintronics
- Published
- 2025-01-27
- DOI
- https://doi.org/10.1038/s44306-024-00068-7
- Citations
- 4
- Primary Topic
- Magnetic properties of thin films
- Type
- article
- Field-Weighted Citation Impact
- 4.99
Funders
- European Commission
- Deutsche Forschungsgemeinschaft
- Helmholtz-Zentrum Dresden-Rossendorf
- European Research Council