[25p-12K-1~9] 13.6 Nanostructures, quantum phenomena, and nano quantum devices

3:00 PM - 3:15 PM JST(6:00 AM - 6:15 AM UTC)English Presentation

[25p-12K-6] Little-Parks effect in InAs/Al and GaAs/InAs/Al fullshell nanowire Josephson junctions

〇(PC)Patrick Zellekens^1,3, Russell Deacon^1,3, Farah Basaric^2,4, Michael Randle^1,3, Detlev Gruetzmacher^2,4, Alexander Pawlis^2,4, Thomas Schaepers^2,4, Koji Ishibashi^1,3 (1.CEMS, RIKEN, 2.PGI, FZ Juelich, 3.ADL, RIKEN, 4.JARA-FIT)

Keywords:

Josephson junctions,Topological systems,Mesoscopic transport

Parafermionic excitations such as Majorana fermions/Majorana zero modes (MZMs) have been proposed as a way to build novel quantum bit structures. One of the most promising concepts for identifying these exotic particles is based on the formation of supercurrent "lobes" separated by dissipative transport, known as the Little-Parks effect. The latter is caused by a periodic modulation of the critical temperature of a superconductor as a function of an applied magnetic flux and the thereby induced “winding” of the superconducting order parameter. A promising platform to study this effect are semiconductor nanowires, e.g. InAs, that are fully surrounded by an epitaxial superconducting Al shell. Here, the required in-plane magnetic field is only determined by the diameter of the nanowire and can be one or two orders of magnitude smaller than for the “traditional” approach that requires the actual opening of a helical gap by using the Zeeman effect. We present low-temperature DC and microwave spectroscopy measurements on InAs/Al and GaAs/InAs/Al half- and fullshell nanowires for various magnetic field configurations and gate voltages.