Spintronics is a dynamic field of research that has given birth to multiple commercial applications of new-generation nanoelectronics utilizing the spin degree of freedom of the electrical current. Identifying suitable materials that host attractive spin-related phenomena is a crucial task in the pursuit of energy-efficient and disruptive computation and memory technologies. Such material discovery can be accelerated by ab initio calculations, which also provide important insights into the underlying physical phenomena. In this thesis, we use a complete set of ab initio computational methods to investigate magnetic and spin transport phenomena at interfaces and 2D materials, utilizing density functional theory (DFT), Wannier functions and tight-binding models for the electronic ground state, in conjunction with Landauer-Büttiker, Kubo and Valet-Raimondi quantum transport formalisms. (1) We provide microscopic explanations for the experimentally observed decrease of Dzyaloshinskii-Moriya interaction (DMI) and a double transition of the sign of magnetic anisotropy in Pt/Co/Al/AlOx heterostructures with an increasing Al insertion thickness. (2) We show that Cr2Te3 films should exhibit an anomalous Hall effect sign reversal, confirming experimental observations, besides addressing the films’ structural and magnetostatic properties. (3) We predict that asymmetrical Janus CrXY monolayers can serve as an all-in-one platform for field-free spin-orbit torque (SOT)-switched perpendicular magnetic random access memories (MRAM). (4) We demonstrate the role of disorder and vertex corrections in ab initio SOT calculations, based on the newly developed kinetic theory of Valet and Raimondi. (5) We finally propose a plausible explanation for the switching mechanism of the technologically important ferroelectric Rashba semiconductor GeTe. The supplementary results address the role of a hybrid functional for ab initio spin expectation values, magnetostatic properties of PdNi binary alloys, spin-transfer torque (STT) in a graphene lateral spin valve and a possible inverse effect of the recently coined 3m torque.

Plus d'information :https://www.spintec.fr/phd-defense-multiscale-modeling-of-spin-orbitronic-phenomena-at-metal-oxide-and-2d-material-interfaces-for-spintronic-devices/
​

Pour suivre la soutenance ​​​en visioconférence : https://univ-grenoble-alpes-fr.zoom.us/j/94186593072?pwd=IX1RzeKj0nu9V9Dk30cJkO49RdBa20.1​

​
​​