SFB Extra Seminar

Josephson junctions are the building blocks of superconducting electronics. They are made of two superconductors separated by an insulating barrier. I will present two experiments where the insulating barrier is replaced by a semiconductor. In the first one [1], we study nanowires where the number of electrons can be controlled, one by one, until a metal-insulator transition is induced. Across this transition, we observed the evolution of the Andreev spectrum that leads to the Josephson effect. In the second experiment [2], we study the Josephson effect in thin films where the electron motion is coupled to its spin. This spin-orbit interaction plays a key role in the discovery of new topological phases of matter. I will show that spin-orbit coupling can be probed by phase sensitive measurements of the Josephson current.

[1] A. Assouline, et al. “Shiba bound states across the mobility edge in doped InAs nanowires”, Phys. Rev. Lett. 119, 097701 (2017).

[2] A. Assouline et al. “Spin-Orbit induced phase-shift in Bi₂Se₃ Josephson junctions”, Nature Communications 10, 126 (2019).