Effect of potential relief on superconductivity revealed by time variations in YBaCuO superconductor properties under illumination

Abstract

Dopant impurity ions affect the motion of the hole carriers not only by means of providing the holes in the conductive plane but also by creating an aperiodic potential relief consisting of wide potential wells. Photoillumination of the sample, redistributing impurity ions over the CuO x chain plane, varies both the number of hole carriers n ( n-process) and the potential relief ( s-process). In the present work these processes were separated in the course of the photoillumination by using a large difference in their characteristic times. As a result, it was found that the s-process essentially affects the critical temperature of superconductivity. A mechanism is proposed which realizes the connection of superconductivity with the potential relief and naturally explains the observed regularities.