Dynamics of the dendritic flux instability in films
Universität Konstanz - Universitätsstr. 10, 78464 Konstanz, Germany
Corresponding author: Bjoern.Biehler@uni-konstanz.de
Accepted: 2 September 2003
We have studied the dynamics of magnetic-flux avalanches in superconducting films by means of a fast magneto-optic pump-probe technique. Two regimes of propagation are found: in regime I, directly after the nucleation of the avalanches by a femtosecond laser pulse, the velocity v of the flux dendrites depends strongly on the magnetic field, and values of v up to 180 are observed. Within some ten nanoseconds after nucleation regime II is reached, where the propagation velocity has dropped by one order of magnitude and is nearly independent of sample temperature and magnetic field. Comparison with previous experiments on flux jumps in superconductors shows good qualitative agreement.
PACS: 74.72.Bk – Y-based cuprates / 74.78.Bz – High- films / 74.25.Qt – Vortex lattices, flux pinning, flux creep
© EDP Sciences, 2003