Erhöhung der maximalen Geschwindigkeit für die Abrikosov-Vortexdynamik
Zusammenfassung der Projektergebnisse
The main goal of the project "Enhancing speed limits to the Abrikosov vortex dynamics" was to experimentally probe and enhance the speed limits of the vortex dynamics at strong dc currents and/or high ac frequencies: the instability velocity v*, the instability current density j*, and the depinning frequency fd. To this end, superconducting Nb films were patterned with carefully designed linearly extended pinning "sites" by the direct-write nanofabrication techniques of focused ion beam (FIB) milling and focused electron beam induced deposition (FEBID). Investigations of fast vortex dynamics were carried out by a combination of electrical voltage measurements and broadband microwave spectroscopy. Among most important results obtained are the enhancement of the instability critical parameters and the depinning frequency for a matching configuration of the vortex lattice with the periodic pinning landscape; detection of the radiofrequency and microwave generation from superconducting films using a periodic meander antenna or the intrinsic periodicity of superconductor/insulator superlattices; determination of the pinning potential coordinate dependence from data on the vortex-related absorbed microwave power; observation of the stimulation of superconductivity by a microwave ac stimulus in the vortex state; and achievement of vortex velocities above 3 km/s in consequence of a collective ordering in the vortex guiding regime. The obtained results advance realizations of strongly non-equilibrium regimes in superconductor/ferromagnet heterostructures and investigations of the dynamics of topological defects in superconducting nanoarchitectures.
Projektbezogene Publikationen (Auswahl)
- Microwave emission from superconducting vortices in Mo/Si superlattices. Nature Communications 9, 4927 (2018)
O. V. Dobrovolskiy, V. M. Bevz, M. Yu. Mikhailov, O. I. Yuzephovich, V. A. Shklovskij, R. V. Vovk, M. I. Tsindlekht, R. Sachser, and M. Huth
(Siehe online unter https://doi.org/10.1038/s41467-018-07256-0) - Fast dynamics of guided magnetic flux quanta. Physical Review Applied 11 (2019) 054064
O. V. Dobrovolskiy, V. M. Bevz, E. Begun, R. Sachser, R. V. Vovk, and M. Huth
(Siehe online unter https://doi.org/10.1103/physrevapplied.11.054064) - Moving flux quanta cool superconductors by a microwave breath. Communications Physics 3 (2020) 64
O. V. Dobrovolskiy, C. Gonzalez-Ruano, A. Lara, R. Sachser, V. M. Bevz, V. A. Shklovskij, A. I. Bezuglyj, R. V. Vovk, M. Huth, F. G. Aliev
(Siehe online unter https://doi.org/10.1038/s42005-020-0329-z) - Upper frequency limits for vortex guiding and ratchet effects. Physical Review Applied 13 (2020) 024012
O. V. Dobrovolskiy, E. Begun, V. M. Bevz, R. Sachser, and M. Huth
(Siehe online unter https://doi.org/10.1103/physrevapplied.13.024012)
