Anisotropic thermomagnetic avalanche activity in field-cooled superconducting films

Autor: Colauto, Fabiano, Carmo, Danusa do, Andrade, Antonio Marcos Helgueira de, Oliveira, Ana Augusta Mendonça de, Ortiz, Wilson Aires, Johansen, Tom Henning
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Repositório Institucional da UFRGS
Universidade Federal do Rio Grande do Sul (UFRGS)
instacron:UFRGS
Popis: The electrodynamic behavior of isotropic superconducting Nb films cooled below their critical temperature in the presence of in-plane applied magnetic fields is investigated using magneto-optical imaging. A specially designed local flux injector is used to show that the frozen-in in-plane vortices strongly guide and enhance the penetration of perpendicular vortices, whereas their penetration across the array of in-plane vortices is essentially unchanged. This result provides the key to understanding why field-cooled square superconducting films show anisotropic nucleation of flux avalanches (jumps) along the four edges. The explanation is based on an analytical model for thermomagnetic avalanche nucleation in type-II superconducting films, and allows one to understand the entire scenario of different flux dynamics observed experimentally.
Databáze: OpenAIRE