Ultrafast spin-currents and charge conversion at 3d-5d interfaces probed by time-domain terahertz spectroscopy

Authors

T. H. Dang, Universite Paris-Saclay
J. Hawecker, École Normale Supérieure
E. Rongione, Universite Paris-Saclay
G. Baez Flores, University of Nebraska–Lincoln
D. Q. To, Universite Paris-Saclay
J. C. Rojas-Sanchez, Universite Paris-Saclay
H. Nong, École Normale Supérieure
J. Mangeney, École Normale Supérieure
J. Tignon, École Normale Supérieure
F. Godel, Universite Paris-Saclay
S. Collin, Universite Paris-Saclay
P. Seneor, Universite Paris-Saclay
M. Bibes, Universite Paris-Saclay
A. Fert, Universite Paris-Saclay
M. Anane, Universite Paris-Saclay
J. M. George, Universite Paris-Saclay
L. Vila, Universite Grenoble Alpes
M. Cosset-Cheneau, Universite Grenoble Alpes
D. Dolfi, Thales Research and Technology
R. Lebrun, Universite Paris-Saclay
P. Bortolotti, Universite Paris-Saclay
Kirill Belashchenko, University of Nebraska - LincolnFollow
S. Dhillon, École Normale SupérieureFollow
H. Jaffrès, Universite Paris-SaclayFollow

ORCID IDs

E. Rongione https://orcid.org/0000-0002-3775-2543

J. C. Rojas-Sanchez https://orcid.org/0000-0001-7044-2785

J. Tignon https://orcid.org/0000-0002-7599-9889

F. Godel https://orcid.org/0000-0003-1741-2741

M. Bibes https://orcid.org/0000-0002-6704-3422

M. Anane https://orcid.org/0000-0001-5396-6165

L. Vila https://orcid.org/0000-0002-1171-2391

K. Belashchenko https://orcid.org/0000-0002-8518-1490

H. Jaffrès https://orcid.org/0000-0002-2730-1255

Document Type

Article

Date of this Version

12-1-2020

Citation

Appl. Phys. Rev. 7, 041409 (2020);

doi: 10.1063/5.0022369

Comments

Published under license by AIP Publishing. Used by permission.

Abstract

Spintronic structures are extensively investigated for their spin-orbit torque properties, required for magnetic commutation functionalities. Current progress in these materials is dependent on the interface engineering for the optimization of spin transmission. Here, we advance the analysis of ultrafast spin-charge conversion phenomena at ferromagnetic-Transition metal interfaces due to their inverse spin-Hall effect properties. In particular, the intrinsic inverse spin-Hall effect of Pt-based systems and extrinsic inverse spin-Hall effect of Au:W and Au:Ta in NiFe/Au:(W,Ta) bilayers are investigated. The spin-charge conversion is probed by complementary techniques-ultrafast THz time-domain spectroscopy in the dynamic regime for THz pulse emission and ferromagnetic resonance spin-pumping measurements in the GHz regime in the steady state-to determine the role played by the material properties, resistivities, spin transmission at metallic interfaces, and spin-flip rates. These measurements show the correspondence between the THz time-domain spectroscopy and ferromagnetic spin-pumping for the different set of samples in term of the spin mixing conductance. The latter quantity is a critical parameter, determining the strength of the THz emission from spintronic interfaces. This is further supported by ab initio calculations, simulations, and analysis of the spin-diffusion and spin-relaxation of carriers within the multilayers in the time domain, permitting one to determine the main trends and the role of spin transmission at interfaces. This work illustrates that time-domain spectroscopy for spin-based THz emission is a powerful technique to probe spin-dynamics at active spintronic interfaces and to extract key material properties for spin-charge conversion.