Presentation

The activities of the CryoQuant Division at the Technische Universität Braunschweig have been concerned with the development of superconductor electronic devices operated in a transient regime between the Josephson and Abrikosov fluxonics. On the side of materials science, this has been achieved via i) tuning the interlayer coupling strength in superconductor/semiconductor superlattices [1], ii) exploiting nonequilibrium superconducting states at large dc currents [2] and microwave ac frequencies [3], as well as confining the motion of fluxons in Josephson microbridges [4] and superconductor 3D nanoarchitectures [5]. At the facet of applications, microwave generators in the 1–50 GHz range [1], dynamically formed Josephson junctions [2], coplanar waveguides with microwave-stimulated current-carrying capability [3], fluxon counters/velocimeters [4], and generators of spin waves of the Cherenkov-Josephson type [6] have been demonstrated. Further activities of the group are concerned with novel computing concepts and the integration of fluxonic devices with other technologies, targeting at applications in metrology, bolometry, and quantum particles counting.

Publications

[1] 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, “Microwave emission from superconducting vortices in Mo/Si superlattices,” Nat. Commun., vol. 9, pp. 4927-1-9, Nov. 2018, doi: 10.1038/s41467-018-07256-0

[2] O. V. Dobrovolskiy, D. Yu. Vodolazov, F. Porrati, R. Sachser, V. M. Bevz, M. Yu. Mikhailov, A. V. Chumak, and M. Huth, “Ultra-fast vortex motion in a direct-write Nb-C superconductor,” Nat. Commun., vol. 11, pp. 43291-1-10, Jul. 2020, doi: 10.1038/s41467-020-16987-y

[3] O. V. Dobrovolskiy, C. Gonzalez-Ruano, A. Lara, R. Sachser, V. M. Bevz, V. A. Shklovskij, A. I. Bezuglyj, R. V. Vovk, M. Huth, and F. G. Aliev, “Moving flux quanta cool superconductors by a microwave breath,” Commun. Phys., vol. 3, pp. 64-1-11, Apr. 2020, doi: 10.1038/s42005-020-0329-z

[4] V. M. Bevz, M. Yu. Mikhailov, B. Budinska, S. Lamb-Camarena, S. O. Shpilinska, A. V. Chumak, M. Urbanek, M. Arndt, W. Lang, and O. V. Dobrovolskiy, “Vortex counting and velocimetry for slitted superconducting thin strips,” Phys. Rev. Appl., vol. 19, pp. 034098-1-11, Mar. 2023, doi: 10.1103/PhysRevApplied.19.034098

[5] I. Bogush, O. V. Dobrovolskiy, and V. M. Fomin, “Microwave generation and vortex jets in superconductor nanotubes,” Phys. Rev. B, vol. 109, pp. 104516-1-12, Mar. 2024, doi: 10.1103/PhysRevB.109.104516

[6] O. V. Dobrovolskiy, D. Yu. Vodolazov, F. Porrati, R. Sachser, V. M. Bevz, M. Yu. Mikhailov, A. V. Chumak, and M. Huth, “Magnon-Cherenkov effect in superconductor-ferromagnet heterostructures,” ResearchSquare, pp. 1-7, Aug. 2024, Art. no rs-4807057, doi: 10.21203/rs.3.rs-4807057/v1