高温超导体中磁通涡旋的量子隧道效应——TlBaCaCuO化合物磁弛豫的实验研究  

QUANTUM TUNNELLING OF VORTICES IN HIGH T C SUPER CONDUCTORS:MAGNETIC RELAXATION EXPERIMENTS IN TIBaCaCuO COMPOUNDS

作　　者：张西祥 白海力 A.Garcia 姜恩永 T.Tejada 

出　　处：《物理学进展》1996年第2期215-228,共14页Progress In Physics

摘　　要：本文报道了ＴｌＢａＣａＣｕＯ超导体（２２１２，２２２３单相，多晶及薄膜材料）中磁弛豫现象的实验结果。从实验上证实了通量运动由热激活到非热激活机制的转变。实验中得到的与温度无关的磁弛豫速率与由通量运动量子隧道效应理论计算结果相一致。Magnetic relaxation experiments in TlBaCaCuO supercoductors (2212 and 2223 single phases,polycrystalline and thin films materials) are reported.The results give evidence of a crossover from thermally to non thermally activated flux motion.The temperature independent magnetic relaxation rates (below～6 K and～3K for the 2212 and 2223 phase respectively)compare well with the values calculated according to the theories of flux motion by quantum tunnelling.The effect of anisotropy and magnetic field on the quantum creep rate is discussed.

关 键 词：高温 超导体 量子隧道效应 TBCCO 磁弛豫 

分 类 号：O511.1[理学—低温物理] TM263[理学—物理]