第2类超导体中无序钉扎环境下的尖峰效应

Disorder induced peak effect in the type-Ⅱ superconductors

用分子动力学方法模拟了第2类超导体的尖峰效应,结果表明尖峰效应的位置正好在单磁通钉扎转变到多磁通钉扎的温度区域.在温度接近Tc时,涡旋运动速度出现大幅度下降,暗示系统的临界电流大幅度增加.此外,借助Wang-Landau算法,对涡旋在Tc附近的行为进行了分析,结果表明:温度接近于临界温度时,磁通的尺寸大幅度增加,钉扎作用范围变大,钉扎能够容纳涡旋的个数也逐渐增加.

The peak effect of the type-II superconductor is studied by molecular dynamics.The peak effect just occurs at the temperature regime where the single vortex pinning crossovers to the multi-vortices pinning.Around Tc,the average velocity of vortices decreases considerably,implying that the critical current of the system increases rapidly.By using Wang-Landau algorithm,we analyze the vortices behavior near the critical temperature.When temperature approaches Tc,the size of flux,the interaction range of pinning,and the number of pinned vortices per pinning center increase.