Flux flow instability in type II superconducting strips: Spatially uniform versus nonuniform transition
Institute for Physics of Microstructures, Russian Academy of Sciences, Nizhny Novgorod 603950, GSP-105, Russia
Received November 25, 2019, published online February 28, 2020
We discuss two possible mechanisms of the flux flow instability (FFI) in type II superconducting strips. While the nature of nonequilibrium effects leading to this instability is widely accepted (Joule heating and finite relaxation time of the superconducting order parameter) still there is a question how FFI develops in space. According to one scenario instability occurs simultaneously in the whole sample and superconductor jumps to the normal or resistive state with no change in the structure of moving vortex array. Another scenario predicts appearance of the vortex rivers at the instability point and jump of the superconductor to the normal or the resistive state but with strongly modified structure of the moving vorticies.
Key words: flux flow instability, Joule heating, order parameter relaxation time.