Guiding thermomagnetic avalanches with soft magnetic stripes

Article

关键词: CRITICAL-CURRENT DENSITY;    MGB2 THIN-FILMS;    FLUX AVALANCHES;    SUPERCONDUCTORS;    INSTABILITIES;    PENETRATION;    STABILITY;    STATE;    FIELD;    MODEL;   

DOI  :  10.1103/PhysRevB.96.214510

来源: SCIE

【 摘 要 】

We demonstrate the potential for manipulating the ultrafast dynamics of thermomagnetic flux avalanches (TMA) in superconducting films with soft magnetic stripes deposited on the film. By tuning the in-plane magnetization of the stripes, we induce lines of strong magnetic potentials for Abrikosov vortices, resulting in guided slow motion of vortices along the stripe edges and preferential bursts of TMA along the stripes. Furthermore, we show that transversely polarized stripes can reduce the TMA size by diverting magnetic flux away from the major trunk of the TMA into interstripe gaps. Our data indicate that TMAs are launched from locations with enhanced vortex entry barrier, where flux accumulation followed by accelerated vortex discharge significantly reduces the threshold of the applied field ramping speed required for the creation of TMAs. Finally, vortex-antivortex annihilation at the moving front of an expanding TMA can account for the enhanced TMA activity in the receding branches of the sample's magnetization cycle and the preferred propagation of TMAs into maximum trapped flux regions.

【 授权许可】

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