London磁场的物理机制研究

Physical mechanism of London moment

超导体在旋转过程中会在其内部产生磁场,称为London磁场.目前,包括London理论和G-L理论在内的多种理论都对London磁场的产生机理进行了解释.从本质上,这些理论解释大多认为旋转超导体最外层超导电子运动滞后并由此出现净余电流,而London磁场则是由旋转超导体表面的净余电流产生的.然而,关于旋转超导体最外层超导电子运动滞后的原因,目前仍没有明确的理论解释.本文通过对旋转系中带电粒子,以及旋转超导体中超导电子的贝里相位进行了理论分析,结果表明旋转状态下超导电子的贝里曲率与London磁场具有相同的表达形式,表明London磁场可视为A-B效应的逆效应,也即基于贝里相位的一种宏观量子效应.

The superconductor will generate a magnetic field inside the superconductor during its rotation,which is called the London moment.At present,a variety of theories including London theory and G-L theory have explained the generation mechanism of London moment.Most of these theories essentially believe that the superconducting electrons in the surface layer of the rotating superconductor lag behind and have a net residual current.The London moment is produced by the net residual current on the surface of the rotating superconductor.However,there is still no clear theoretical explanation for the motion lag of the outermost superconducting electrons in rotating superconductors.In this paper the charged particles in the rotating system and the Berry phase of the superconductor in the rotating superconductor are analyzed.The results show that the Berry curvature of the superconductor has the same expression form as the London moment,indicating that the London moment may be the inverse effect of A-B effect,which is a macroscopic quantum effect based on Berry phase.