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Origin of the Laser‐Induced Picosecond Spin Current Across Magnetization Compensation in Ferrimagnetic GdCo
Author(s) -
Nava Antonio Guillermo,
Remy Quentin,
Lin JunXiao,
Le Guen Yann,
Hamara Dominik,
ComptonStewart Jude,
Barker Joseph,
Hauet Thomas,
Hehn Michel,
Mangin Stéphane,
Ciccarelli Chiara
Publication year - 2025
Publication title -
advanced optical materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.89
H-Index - 91
ISSN - 2195-1071
DOI - 10.1002/adom.202500056
Subject(s) - ferrimagnetism , materials science , magnetization , condensed matter physics , spin current , picosecond , current (fluid) , compensation (psychology) , spin (aerodynamics) , laser , optics , magnetic field , physics , psychology , quantum mechanics , psychoanalysis , thermodynamics
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.