Affiliation
Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU
Web
Talk Title
Magnetoelectric Effects and Nonreciprocal Transport in Superconductors and Josephson Junctions
Abstract
Non-reciprocal transport effects have been proposed and observed in various structures, driven by the search for a superconducting diode, i.e. a superconducting device with a critical current dependent on the direction of the applied current. In the first part of this presentation, I will discuss the superconducting diode effect and its connections with other, hitherto unconnected phenomena such as the spin-galvanic effect, anomalous supercurrents, the superconducting helical phase, and magnetoelectric effects induced by isotropic spin-orbit coupling. I will show that besides broken time-reversal symmetry, a common feature of these effects is that they appear in systems with gyrotropic symmetry, realized on different scales [1,2].
In the second part, I will present an effective low-energy field theory that offers a unified description of transport in diffusive normal and superconducting metals with generic spin-orbit coupling, based solely on fundamental symmetry constraints [3]. I will place a particular focus on magnetoelectric and non-reciprocal effects. In light of this theoretical framework, I will discuss some predictions and recent experimental findings [4].
References
[1] T. Kokkeler, I. V. Tokatly, and F. S. Bergeret, SciPost 16, 055 (2024).
[2] W.-Y. He and K. T. Law, Phys. Rev. Res. 2, 012073 (2020).
[3] T. Kokkeler, F. S. Bergeret, and I. V. Tokatly, arXiv preprint arXiv:2405.06334 (2024).
[4] S. Ilic,P. Virtanen, D. Crawford, T. T. Heikkilä, and F. S. Bergeret, arXiv preprint arXiv:2406.17046 (2024).