PhD thesis defense: spin-to-charge current interconversion in highly resistive sputtered bismuth selenide

CIC nanoGUNE Seminars

Speaker

Isabel C. Arango
Pre-Doctoral Researcher at CIC nanoGUNE

When

2023/11/27
11:30

Place

Sala de actos, Facultad de Química (UPV/EHU), Paseo Manuel Lardizabal, 3, 20018 Donostia, Gipuzkoa

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The development of spin-orbitonic devices, such as the magneto-electric spin-orbit (MESO) logic devices proposed by Intel, requires materials with high resistivity and high spin-to-charge interconversion efficiency. One of the most promising candidates in this regard is sputtered Bi_xSe_1-x. Although there are several techniques to quantify spin-to-charge interconversion, the reported values for sputtered Bi_xSe_1-x have often been overestimated due to spurious effects related to local currents combined with a lack of understanding of the effect of interfaces and the use of approximations for unknown parameters such as the spin diffusion length. In this thesis we systematically study the spin transport properties of the polycrystalline sputtered Bi_xSe_1-x by different spin-to-charge interconversion techniques.  The results of this thesis highlight the importance of considering all the details of Bi_xSe_1-x  and its interfaces in order to properly quantify the spin transport properties of this material, something that is unfortunately neglected in many studies. Although the existing literature has reported a high SCI efficiency for Bi_xSe_1-x and presented this material as a promising candidate for MESO logic devices, our work shows otherwise.