Origin of the Laser‐Induced Picosecond Spin Current Across Magnetization Compensation in Ferrimagnetic GdCo
Abstract The optical manipulation of magnetism enabled by rare earth‐transition metal ferrimagnets holds the promise of ultrafast, energy‐efficient spintronic technologies. This work investigates laser‐induced picosecond spin currents generated by ferrimagnetic GdCo via terahertz emission spectroscopy. A suppression of the THz emission and spin current is observed at magnetization compensation when varying the temperature or alloy composition in the presence of a magnetic field. It is demonstrated that this is due to the formation of domains in the GdCo equilibrium magnetic configuration. Without an applied magnetic field, the picosecond spin current persists at the compensation point. The experimental findings support the model for THz spin current generation based on the transport of hot spin‐polarized electrons, which is dominated by the Co sublattice at room temperature. Only at low temperature a comparable contribution from Gd is detected but with slower dynamics. Finally, spectral analysis reveals a blueshift of the THz emission related to the formation of magnetic domains close to magnetization compensation.
Authors
- Chiara Ciccarelli (ORCID: https://orcid.org/0000-0003-2299-3704)
- Joseph Barker (ORCID: https://orcid.org/0000-0003-4843-5516)
- Jun‐Xiao Lin (ORCID: https://orcid.org/0000-0003-4763-8514)
- S. Mangin (ORCID: https://orcid.org/0000-0001-6046-0437)
- Thomas Hauet
- Guillermo Nava Antonio (ORCID: https://orcid.org/0000-0003-2813-2841)
- M. Hehn (ORCID: https://orcid.org/0000-0002-4240-5925)
- Dominik Hamara (ORCID: https://orcid.org/0000-0001-7318-8161)
- Yann Le Guen (ORCID: https://orcid.org/0009-0005-4990-2210)
- Jude Compton‐Stewart (ORCID: https://orcid.org/0000-0002-8243-1132)
- Quentin Remy (ORCID: https://orcid.org/0000-0002-4801-3199)
Institutions
- Centre National de la Recherche Scientifique (FR)
- University of Leeds (GB)
- University of Cambridge (GB)
- Institut Jean Lamour (FR)
- Freie Universität Berlin (DE)
- Université de Lorraine (FR)
Publication Details
- Journal
- Advanced Optical Materials
- Published
- 2025-02-13
- DOI
- https://doi.org/10.1002/adom.202500056
- Citations
- 3
- Primary Topic
- Magnetic properties of thin films
- Type
- article
- Field-Weighted Citation Impact
- 3.74
Funders
- UK Research and Innovation
- Leverhulme Trust
- Royal Society
- European Commission
- Agence Nationale de la Recherche
- Ministère de l'Europe et des Affaires Étrangères
- Ministère de l'Education Nationale, de l'Enseignement Superieur et de la Recherche
- H2020 European Research Council