非平衡辐射响应与准二维高温超导体系的磁通涡旋激发

从实验上揭示了高温超导体YBa₂Cu₃O_{7-δ(YBCO)颗粒膜具有准二维结构的输运特征以及超导弱连接行为特征.在此基础上，将超导颗粒膜样品等效为准二维Josephson弱连接阵列系统，讨论了电流引起的二维超导体系中磁通“涡旋-反涡旋”束缚对的拆对激发问题，并给出了自由涡旋分布n(T,I)的分析表达式.将颗粒膜样品的非平衡辐射响应测量结果与电流激发自由涡旋分布n(T,I)相比较，两者具有相似的分布特征.该结果表明，高温超导体颗粒膜 关键词：}

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 T_KT.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-T_c superconducting granular films.