With the recent proposals of the Magneto-Electric Spin-Orbit coupling device (MESO) by Intel and the Ferro-Electric Spin-Orbit coupling device (FESO) by our group, spin logic had gained a primal role in spintronics aiming to compete with CMOS technology. The study of the spin-charge interconversion phenomena became an important topic and finding the best material for such application is crucial. Heavy metals show efficiency limits and new materials possessing large interconversion are needed in order to fulfill the requirements of the new spin logic circuits. In this context, the study of the interconversion properties in topological insulators and alternative materials is required. The high resistivity typical of semiconductors and insulators combined with large interconversion efficiencies might help closing the gap between research and technological requirements. In the first chapter, we introduce the discovery of the spin-charge interconversion and the relevant physics necessary to understand those phenomena. The second chapter focus the attention in the measurement of the spin-charge interconversion in sputtered antimony telluride (Sb2Te3), a topological insulator. The results show a sizeable interconversion at low temperature in nanodevices and the role of nanofabrication in altering the crystal structure. The third chapter presents spin-charge interconversion in another relevant class of material with a large momentum in spintronics: ferroelectric Rashba semiconductors (FERSC). Germanium telluride (GeTe) is part of this class of materials, which are capable of controlling the sign and the amplitude of the spin-charge interconversion by the ferroelectric state of the material. The ferroelectricity adds a new degree of freedom for spin-charge interconversion; also, this chapter stress the role of the interfacial layer and the deposition condition for the optimization of the generated signal. A small part is dedicated to the proposal of a new design for nanodevices for better signal detection. The last chapter is devoted to the state of the art of magnetic random access memories (MRAM), a technology proposed in the 90’s harnessing the non-volatility properties of ferromagnetic materials which has evolved and was able to be commercialized as memories in only 20 years. We propose a deeper analysis of the in-plane field required in perpendicularly magnetized magnetic tunnel junctions (p-MTJs), the most recent solutions for MRAM, to switch deterministically their state by using torques generated by a spin-orbit coupling layer (pSOT-MRAM). This part consists in the proposition of a novel measurement technique for the estimation of the in-plane field and novel analytical models predicting the critical current density and pulse duration required to switch pSOT-MRAM

Plus d'information :https://www.spintec.fr/phd-defense-spin-charge-interconversion-nanodevices-based-on-telluride-materials-for-low-power-computing/
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Pour suivre la soutenance ​​​en visioconférence : https://univ-grenoble-alpes-fr.zoom.us/j/3241920232​

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