Description du sujet de thèse

ontext: Orbitronics, which uses the orbital angular momentum as a new degree of freedom, is a brand-new field of research with highly-promising perspectives to strongly enhance the capabilities of current spintronic devices (non-volatile memories, radio-frequency oscillators, magnetic sensors) [1]. The use of orbital currents should indeed allow to significantly reduce the energy consumption of such devices and also to avoid the use of costly and toxic heavy metals. orbital momentum in solids being intrinsically linked to the crystal field, using oxides appears as a natural way to generate strong and easily-tunable orbital currents; surprisingly, up-to-now, noinvestigations have been carried out on these materials.

Goals: During the PhD, we propose to calculate numerically the orbital moments associated to electronic bands which could participate
to transport properties in oxides, and which could thus help experimentally generating significant orbital currents. To obtain sufficiently-high orbital momentum, we will tune the electronic structure either by changing the chemical composition or by applying mechanical strain to distort the lattice and suitably modify the crystal field. Calculations of the electronic and magnetic properties in the vicinity of interfaces with metal and ferroelectric materials will later be envisioned to describe realistic devices which will be jointly measured by our experimentalist colleagues.

Ab initio numerical calculations of the electronic structure will be performed using the density functional theory (DFT). A few code developments will be needed to compute the orbital moments from the obtained DFT results [2,3].

Prerequisite: The candidate will possess a Master degree and have a good knowledge of condensed-matter and quantum physics, a strong interest for numerical physics, and good communication skills (oral and writing). Correct mastery of at least one programming language is also desired.


Bibliography:
[1] D. Go, et al., Europhys. News 55/2, 28 (2024).
[2] A. Pezo, et al., Phys. Rev. B 108, 075427 (2023).
[3] A. Pezo, et al., Phys. Rev. B 111, L140405 (2025).

Contexte de travail

The PhD will be supervised by Dr. Rémi Arras (CEMES, Toulouse) and Pr. Aurélien Manchon (CINaM, Marseille). It will take place at the CEMES laboratory in Toulouse, will start during Fall 2025 for a duration of 3 years and it will be funded by the project Oxide materials for orbitronics (OXIMOR), which is part of the national project PEPR-SPIN (https://www.pepr-spin.fr/). The project OXIMOR gathers experimentalists and theoreticians from 6 laboratories, with whom regular scientific exchanges will be maintained.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.