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Spin Injection Efficiency at Metallic Interfaces Probed by THz Emission Spectroscopy
Author(s) -
Hawecker Jacques,
Dang ThiHuong,
Rongione Enzo,
Boust James,
Collin Sophie,
George JeanMarie,
Drouhin HenriJean,
Laplace Yannis,
Grasset Romain,
Dong Jingwei,
Mangeney Juliette,
Tig Jerome,
Jaffrès Henri,
Perfetti Luca,
Dhillon Sukhdeep
Publication year - 2021
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.202100412
Subject(s) - spin pumping , spintronics , terahertz radiation , condensed matter physics , materials science , ultrashort pulse , ferromagnetism , spin hall effect , ferromagnetic resonance , spectroscopy , spin (aerodynamics) , optoelectronics , spin polarization , magnetic field , physics , optics , laser , magnetization , electron , quantum mechanics , thermodynamics
Terahertz (THz) spin‐to‐charge conversion has become an increasingly important process for THz pulse generation and as a tool to probe ultrafast spin interactions at magnetic interfaces. However, its relation to traditional, steady state, ferromagnetic resonance techniques is poorly understood. Here, nanometric trilayers of Co/X/Pt (X = Ti, Au or an Au:W alloy) are investigated as a function of the “X” layer thickness, where THz emission generated by the inverse spin Hall effect is compared to the Gilbert damping of the ferromagnetic resonance. Through the insertion of the “X” layer it is shown that the ultrafast spin current injected in the non‐magnetic layer defines a direct‐spin‐conductance, whereas the Gilbert damping leads to an effective spin‐mixing‐conductance of the trilayer. Importantly, it is shown that these two parameters are connected to each other and that spin‐memory‐losses can be modeled via an effective Hamiltonian with Rashba fields. This work highlights that magneto‐circuit concepts can be successfully extended to ultrafast spintronic devices, as well as enhancing the understanding of spin‐to‐charge conversion processes through the complementarity between ultrafast THz spectroscopy and steady state techniques.