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TT: Fachverband Tiefe Temperaturen
TT 26: Nanotubes and Nanoribbons
TT 26.2: Talk
Tuesday, March 19, 2024, 09:45–10:00, H 3007
Microwave generation and vortex jets in superconductor nanotubes — •Vladimir M. Fomin1,2, Oleksandr V. Dobrovolskiy3, and Igor Bogush1,2 — 1Leibniz IFW Dresden, IET, 01069 Dresden, Germany — 2Moldova State University, 2009 Chişinău, Republic of Moldova — 3University of Vienna, Nanomagnetism and Magnonics, Superconductivity and Spintronics Laboratory, 1090 Vienna, Austria
The dynamics of superconducting (Abrikosov) vortices determine the resistive response of superconductors. In pinning-free planar thin films, the penetration and motion of vortices are controlled by edge defects, leading to such arrangements as vortex chains, vortex jets, and phase-slip regimes. Relying upon the time-dependent Ginzburg-Landau equation, we predict that these vortex patterns should appear in superconductor open nanotubes even without edge defects, due to the inhomogeneity of the normal magnetic induction component. Distinct from planar thin films, the vortex jets are constrained within the half-tubes and correlate strongly between them. Due to a stronger confinement of single vortex chains in tubes of small radii, we reveal jumps in the average voltage and frequency of microwave generation, which occur when the number of fluxons moving in the half-tubes increases by one. We also realize non-symmetric vortex jets and chains by tilting the magnetic field in the plane perpendicular to the nanotube axis, with a jet-to-chain transition unseen for planar constrictions. In all, our findings are essential for novel 3D superconductor devices, which can operate in few- and multi-fluxon regimes.
Keywords: superconductor open nanonubes; superconducting vortices; vortex chains; vortex jets; microwave generation