NON-EQUILIBRIUM RADIATION RESPONSE AND DECOUPLING OF VORTEX-ANTIVORTES PAIRS IN TWO-DIMENSIONAL HIGH-Tc SUPERCONDUCTORS

On the basis of the two-dimensional (2D) characteristics of the superconducting transportation as well as Josephson weak link behaviors in granular YBCO films,a 2D Josephson junction array is proposed as a model system for this film.Using this simplified model,we have discussed the decoupling procedure of vortex-antivortex pairs by bias current,and analytically developed temperature distribution of free vortices n(T,I) below TKT.As compared with experimental results,we find that the temperature dependency of n(T,I) is similar to the behaviors of microwave response of granular YBCO films near K-T transition temperature.This similarity implies,to a certain extent,some intrinsic relationship between vortex-antivortex decoupling and non-equilibrium radiation response dissipation in the high-Tc superconducting granular films.