Nanoscale physics

Electrodynamics of nanostructured type-II superconductors
Kasatkin A.L.1,2, Shapovalov A.P.2, Shnyrkov V.I.2, Pokusinskii A.O.3
1G.V. Kurdyumov Institute for Metal Physics, 36, Vernadsky bl., 03142 Kiev
E-mail: al_kas@i.ua
2Physical Engineering Teaching Research Center of the NAS of Ukraine (Kiev Academic University), 36, Vernadsky bl., 03142 Kiev
3 Radiophysics Faculty, Kiev T.Shevchenko National University, 4-g Glushkov Ave., 03187 Kiev, Ukraine. 

       Implantation of dielectric nanoparticles in the interior of high-temperature superconductors (HTS) as well as creation of nanosized radiation defects inside HTS now is widely used for fabrication of HTS materials with enhanced current carrying capability. The latter property originates due to gain in Abrikosov vortices pinning caused by insertion of additional nanosized pinning sites and subsequent restriction of dissipative vortex motion through the current loaded superconductor. The most significant effects are achieved when point-like pinning sites for vortices are self-organized in form of extended columnar defects - ‘nanorods’ [1]. Another advantage of such kind treatment of HTS materials concerns their microwave applications. In general case these inserted nanostructural defects allow to decrease the total microwave surface resistance value, eliminate losses due to oscillation of trapped vortices and increase the microwave linear response range [2, 3].    
       In the present work we review experimental and theoretical achievements in physics and technique of nanostructured HTS films and tapes, discuss the most effective mechanisms of vortex pinning and related electrodynamic characteristics.    
K.A.L., S.A.P. and S.V.I. were supported by a joint Ukrainian-German grant from the MES of Ukraine (Project No. M/23-2018).

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