The “echo” effect in response to a current pulse acting on a superconductor in a magnetic field

Abstract

The response of a layered high-temperature superconductor to a current pulse of microsecond duration has been calculated in the framework of a two-dimensional model of a layered HTS. In the external magnetic field, an “echo” effect is observed, i.e., a voltage increase in the sample after the current is completely switched off. This effect is observed at low temperatures and disappears near 70 K. The effect persists when the duration of the current pulse is increased. The effect persists as the duration of the trailing edge of the pulse increases. The occurance of this effect is associated with the flow of the vortex lattice after the transport current is switched off.