'Physique et Chimie des Matériaux' – ED 397 – 2016 Proposition pour allocation de recherche, Thème (A,B,C,D,E):
Unité de recherche (nom, label, équipe interne): Unité Mixte de Physique UMR-137
Adresse : 1 Avenue Augustin Fresnel, 91767 PALAISEAU
Directeur de l’Unité : Frederic Nguyen Van Dau
Etablissement de rattachement : CNRS
Nom du directeur de thèse (HDR), téléphone et courriel : H. Jaffrès ; 01 69 41 58 70 ;
Nombre de thésards actuellement encadrés et années de fin de thèse: 0
Co-encadrant éventuel : P. Bortolotti, 01 69 41 58 38; [email protected]
Titre de la thèse: Spin-current and spin-Hall effect for emission/detection in the THz regime
Description du projet :
THz detection technology represents today a potential solution for both imaging (security issues,
defense applications as control in airports, people screening, IEDs detection…) and also remote sensing
for real time detection and identification (weapons, explosive). In addition, prime importance in radio-
astronomy, security, long-term atmospheric, remote sensing, planetary missions and earth observation.
On the other-hand, the giant Magneto-Resistance (GMR) effect discovered by Albert Fert and his team
at Orsay in 1988, kicked-off the field of spintronics with actual strong applications in devices (read-
heads, MRAM magnetic memories) and potential future new functionalities. Whereas the heart of
GMR and spin-current generation/manipulation, at this stage, relies on the focus of magnetic field
detection at the nanometer scale for industrial application, its response in the THz regime remains
quasi-unexplored. Owing to some very recent article published in high impact factor journal, we may
anticipate a strong response sensitivity of GMR elements to frequency excitation in the THz range
(detection) as well as its potential use as a broad-band source or THz emitter.
In this PhD research program, we propose to investigate both by modeling and experimentally, the
properties of GMR elements under THz excitation (spectroscopy and resistivity) as well as its
fundamentals in term of spin-current profiles within the multilayers stacks. Complementary
experiments and model analyses would also be very beneficial to the direct determination of some
relevant issues and physical parameters of GMR, as spin-dependent momentum relaxation time,
interface charge to spin-orbit conversion (Inverse Edelstein Effect) and spin-orbit assisted diffusion and
transverse spin-current generated by spin-orbit of heavy materials (Au-W, Pt) responsible for dipole
oscillation in the picosecond regime.