Seminar of International Laboratory of High Magnetic Fields and Low Temperatures PAS
ul. Gajowicka 95, sala seminaryjna (nowy budynek, II piętro)
Unusual vortex dynamics in magnetic and high-Tc superconductors
prof. Krzysztof Rogacki
ILHMF< PAS and ILT&SR PAS, Wrocław
Vortex dynamics in magnetic superconductors might be very unusual due to the interaction between magnetism and superconductivity and reflect the competition between these orders. For high temperature superconductors (HTSC), unusual vortex properties are observed as a result of strong thermal fluctuations present in the superconducting state at temperatures even far from Tc. In this review we discuss several intriguing examples of the vortex behavior in magnetic superconductors and HTSC to show the complex nature of the Shubnikov phase in these materials. In particular, the two-step flux penetration process is studied in low-$T_c$ antiferromagnetic superconductors and interpreted as a result of the internal vortex structure with a spin-flop component. For HTSC, the universal character of the Josephson-coupled vortices is shown and analyzed with respect to the melting process of the vortex lattice. Finally, for antiferromagnetic HTSC, we reveal the very well masked interaction between long range magnetic order and superconductivity and show real competition between these effects.
