Speaker
Description
First-principles calculations have recently predicted that chiral materials lacking mirror symmetries---such as twisted van-der-Waals homobilayers---can feature unconventional radial Rashba coupling with spins aligned fully parallel (instead of tangentially) to momentum.
In this talk, we will address Josephson transport through vertical superconductor/ferromagnet/superconductor junctions hosting crossed (radial and tangential) Rashba fields at the interfaces and demonstrate that their interplay with ferromagnetic exchange can lead to supercurrent rectification even when the magnetization is collinear with the current. This so-called unconventional supercurrent diode effect (SDE) originates from spin precessions inside the ferromagnet, which imprint polarity-dependent transmission probabilities on the Cooper pairs being well-distinct from the conventional SDE, and provides a sensitive probe of chiral spin textures.
This work has been supported by Deutsche Forschungsgemeinschaft (DFG; German Research Foundation)---Projects 454646522; 314695032 (SFB 1277).