PhD Thesis Defense | Carmen González Orellana

Exploring the frontiers of ferromagnetic insulator/superconductor-based devices: surface science developments to explain mesoscopic properties

June 22, 15:30

CFM Auditorium

Candidate: Carmen González Orellana

Supervisors:  Maxim Ilin and Celia Rogero Blanco

 DOWNLOAD FULL THESIS

In this Thesis, I study materials at the nanoscale with applicability in quantum technologies, focusing primarily on electromagnetic radiation sensors based on the giant thermoelectric effect. This effect takes place in heterostructures based on superconductors proximitized by a ferromagnetic insulator, which creates a spin imbalance in its density of states, known as spin-splitting. This effect depends on many factors, including the quality of the superconductor/ferromagnetic insulator interface and the properties of all the materials that make up the heterostructure. Combining characterization techniques in ultra high vacuum and ex-situ, I demonstrate how the preparation conditions affect the structural, chemical and magnetic properties of the materials, being able to tune these properties according to the needs of the device where they are implemented. Moreover, I have fabricated tunnel junctions, also studying the manufacturing conditions of each layer, that have an impact on the performance of the device.

Ferromagnetic Insulator/superconductor-based tunnel junction for studying the giant thermoelectric effect