Anisotropic thermomagnetic avalanche activity in field-cooled superconducting films

Article

关键词: FLUX AVALANCHES;    MAGNETIZATION;    DISTRIBUTIONS;    INSTABILITY;    GROWTH;   

DOI  :  10.1103/PhysRevB.96.060506

来源: SCIE

【 摘 要 】

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.

【 授权许可】

Free