Fabrication and measurement of hybrid quantum dot devices featur- ing Yu-Shiba-Rosinov sub-gap states

Abstract: The aim of this bachelor project is to fabricate and study hybrid quantum dot (QD) devices featuring Yu-Shiba-Rosinov (YSR) sub-gap states, made on special InAs nanowires with 7 nm epitaxial aluminum coating on 3 facets. The advantage with these nanowires is the epitaxial aluminum, which can be etched away in a small window of semiconducting nanowire for creating QDs. These dots can be used for measuring the sub-gap states in superconducting materials due to the high degree of tunability. A device with a single QD featuring YSR sub-gap states was fabricated and analyzed, and a double QD system was afterwards made from the device using superconducting leads in the normal state, but not yet featuring YSR sub-gap states. The device does show the possibility for making an superconductor-double dot-superconductor device featuring YSR sub-gap states.