扩展幂律型脱钉和高温超导体及MgB_2的电阻转变  

EXTENDED POWER LAW DEPINNING AND TRANSITION OF RESISTIVITIES OF CUPRATE HTS AND MgB_2

作　　者：胡翔[1] 余增强[1] 宁振华[1] 尹澜[1] 徐晓林[1] 郭建栋[1] 王福仁[1] 尹道乐[1] 

机构地区：[1]北京大学物理学院,北京100871

出　　处：《低温物理学报》2005年第A01期756-763,共8页Low Temperature Physical Letters

基　　金：中国科技部(NKBRSG-G1999064602);国家自然科学基金(项目号10174003;50377040;90303008)资助课题~~

摘　　要：近来,关于无序涡旋物质凝聚体的著名的涡旋玻璃理论受到了来自某些新实验的严重质疑.我们重新审查了高温超导体的临界标度,发现超导混合态的直流伏安特性具有扩展幂律的一般形式.由该扩展幂律型非线性方程模拟的等温线和Strachan等人得到的实验数据[Phys.Rev.Lett.87(2001),067007]符合得很好.文中还讨论了长期以来围绕纵向电阻率和霍尔电阻率的临界指数的某些争议.Recently, the well-known vortex glass theory of the freezing of disordered vortex matter has been severely questioned by some new experiments. We reinvestigate the critical scaling of high-Tc superconductors （HTS） and find that dc current-voltage characteristic of mixed state superconductors has the general form of extended power law. Isotherms simulated from this nonlinear equation well fits the experimental Ⅰ～Ⅴ data of Strachan et al. [Phys. Rev. Lett. 87（2001）, 0670071. Some long debatable controversies surrounding the values of critical exponents of both longitudinal and Hall resistivities are discussed.

关 键 词：扩展幂律 涡旋玻璃 电阻转变 Hall电阻率 

分 类 号：O511.4[理学—低温物理]