STSM of Valeriy Shklovskij at the Goethe University Frankfurt (Germany)
The purpose of the STSM was to adopt the Larkin-Ovchinnikov theory to instability jumps occurring in almost linear current-voltage (I-V) sections of superconductor thin films with different morphology and providing different conditions for Abrikosov vortices. During the STSM, Valeriy Shklovskijworked jointly with Alexei Bezuglyj on the theoretical interpretation of the experimental data obtained on strong-current-driven superconducting Nb films. The basic assumption was that in this case the flux-flow instability is local and it is triggered only in a narrow channel of vortices crossing the superconducting bridge. During the STSM, the derived temperature distribution along the superconducting bridge has been used for an analytical analysis of the current density and the electric field strength at the instability point as a function of the magnetic field value. The obtained theoretical expressions have allowed us to describe the experimental data for Nb films with different pinning conditions for Abrikosov vortices. The results of these studies are detailed in Phys Rev. B 99, 174518 (2019).