Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 97: Superconducting Diodes and Ratchets

TT 97.6: Vortrag

Freitag, 13. März 2026, 11:00–11:15, CHE/0089

Nonreciprocal Magnon Fluxonics — •Oleksandr Dobrovolskiy — Cryogenic Quantum Electronics, EMG and LENA, Technische Universität Braunschweig, Braunschweig, Germany

Fluxon dynamics controls the magneto-resistive response of superconductors (S) and becomes nonreciprocal under symmetry break [1]. Magnons - the quanta of spin waves in magnetic materials - are attracting increasing attention as information carriers [2]. In my talk, I will introduce magnon fluxonics as a subdomain of superconducting spintronics. I will discuss nonreciprocal spin-wave dynamics in dipole-coupled superconductor/ferromagnet heterostructures, focusing on two effects. (i) Within the "ratchet window", the application of an AC current to S enables magnon bandgap tuning during one half-wave, while the bandgap frequencies remain constant during the other. This effect arises from the Doppler shift and the nonlinear spin-wave dispersion. (ii) At higher velocities, on the order of a few km/s, the moving vortex lattice excites magnons unidirectionally along the direction of vortex motion. This regime occurs when the wavevector (momentum) and frequency (energy) of the magnons match those of the fluxons, thereby fulfilling the Cherenkov resonance condition [3]. These results demonstrate how the well-studied superconducting diode or ratchet effects can enrich other research areas and enable new functionalities of nonreciprocal steering and unidirectional generation of spin waves.
[1] Kochan & Strunk, Nat. Electr. 8 (2025) 380.
[2] Chumak et al., IEEE Trans. Magnet. 58 (2022) 0800172.
[3] Dobrovolskiy et al., Nat. Nanotechnol. (2025).
https://doi.org/10.1038/s41565-025-02024-w.

Keywords: Ratchet effect; Abrikosov vortices; Spin waves; Superconductors; Magnonics