Agenda

  Supercurrent rectification and magnetochirality in ballistic Josephson diodes

Christoph Strunk (Regensburg, Germany)

Horaire : le lundi 9 octobre 2023 à 11:00

Lieu : Salle Rémy Lemaire K223, Institut Néel

Résumé : The recent discovery of intrinsic supercurrent diode effect (1), and its prompt observation in a rich variety of systems, has shown that nonreciprocal supercurrents naturally emerge when both space- and time-inversion symmetries are broken. I will report on both dc and ac manifestations of the Josephson diode effect in the non-linear inductance in planar Josephson junctions, based on a ballistic Al/InAs-heterostructure that is exposed to an in-plane magnetic field Bp (2). At low Bp a non-reciprocal term is found in the inductance that is linear in Bp. At higher Bp a sign reversal of the magnetochiral term is observed that can be traced back to a 0-pi-like transition in the current-phase relation (3). Different avenues for a theoretical interpretation are discussed. As pronounced date tunability of both the phi_0 shift and the diode efficiency in an asymmetric SQUID device demonstrates that Rashba spin-orbit interaction provides a substantial contribution to the Josephson diode effect (4).

Ref.: [1] F. Ando et al., Nature 584, 373 (2020). [2] C. Baumgartner et al., Nature Nanotech. 17, 39 (2022). [3] C. Baumgartner et al., Nature Nanotech. (2023). [4] S. Reinhardt et al., arXiv.2308.01061