Orbitronique: temps caractéristiques de la conversion du moment angulaire en charge // Orbitronics: time scales involved in orbital to charge conversion processes

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Orbitronics is an emerging research field spanning condensed matter physics and materials science to electrical engineering that focuses on the study and manipulation of the electron's orbital angular momentum (OAM). The key idea is to use the OAM of electrons as a means to store, transfer, and process information, similar to how spintronics leverages the electron's spin. Importantly, OAM can be generated by a wide range of material systems and with theoretically much higher efficiency than its spin counterpart, using cheap, environmentally friendly and abundant lightweight elements. Orbitronics thus has both a fundamental interest and technological perspectives that provide an innovative and multidisciplinary framework.
Here, we are targeting oxide interfaces as a rich playground to explore Rashba physics in 2D electron gases (2DEG) and in particular its ability to confert spin or orbit to charge via the Orbital Inverse Rashba Edelstein effect. The LaAlO3/SrTiO3 interface provides an ideal playground to explore this physics and in particular parameters such as crystal orientation and the (LaAlO3) tunnel barrier. These properties will be studied at low-temperature as angular momentum is injected in the dc regime by the spin Seebeck effect. The study will be extended to the ultra-fast regime of the orbital to charge conversion using ultra-fast laser-induced demagnetization of a magnetic layer deposited on top and the measurement of the resulting THz emission. Here, we want to identify the parameters responsible for the decrease in efficiency at the picosecond timescale noted in the first THz emission measurements. Our final aim is to measure the timescales associated to hot electrons and spin/orbital diffusion in this system, which will be the main activity of the PhD student.
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Pôle fr : Direction de la Recherche Fondamentale
Département : Institut rayonnement et matière de Saclay
Service : Service de Physique de l’Etat Condensé
Laboratoire : Laboratoire Nano-Magnétisme et Oxydes
Date de début souhaitée : 01-09-2026
Ecole doctorale : Physique en Île-de-France (EDPIF)
Directeur de thèse : VIRET Michel
Organisme : CEA
Laboratoire : DRF/IRAMIS/SPEC/LNO
URL : https://iramis-i.cea.fr/spec/pisp/michel-viret/
URL : https://iramis-i.cea.fr/spec/lno/

Financement public/privé

Pôle fr : Direction de la Recherche Fondamentale
Département : Institut rayonnement et matière de Saclay
Service : Service de Physique de l’Etat Condensé

Master 2