Nonequilibrium Properties of HTSC Under Microwave Irradiation

Abstract

Measurements of the current-voltage characteristics of S-c-N Nb-T1BaCaCuO point contacts have been performed over the temperature range from 4,2K to 300K under applied microwave radiation at a frequency of about 12 GHz. Two types of the excess current dependence on the power P of the external radiation were found. In one case, excess current oscillates with P increase that is explained by the processes of Andreev reflection in S-c-N contacts. In the other case,the excess current is found to be stimulated by the radiation power. Obtained resultes indicate the complicated nature of the quasi-particle spectrum and transport properties of the new superconductors.