arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0909.2311cond-mat.supr-concond-mat.dis-nn
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第二类超导体中的一般critical states

General critical states in type-II superconductors

A. Badía-Majós, C. López, H. S. Ruiz

摘要:

本文采用由物理原理支持的变分理论,在一个广义的框架下,研究了临界态下第二类超导体的磁通量动力学。变分声明和更传统的治疗方法之间的等价性,根据微分麦克斯韦方程组的解决方案,连同适当的电导率的法律。变分方法的优点强调,专注于其数值性能,允许探索新的物理场景。特别是,我们提出了所谓的双临界状态模型的扩展到三维配置中,只有通量运输(T-状态),切割(C-状态)或两种机制(CT-状态)发生。这个理论被应用于几个问题。首先,我们展示了从T态到CT态的转变的特征。其次,我们给出了一个广义表达式的磁通切割阈值在3-D和显示其相关性的板坯的几何形状。此外,几个模型,允许治疗磁通脱钉和切割机制进行了比较。最后,在T和CT条件下分析了纵向输运问题(电流平行于外部磁场施加)。屏蔽和传输之间的复杂的相互作用被解决。

英文摘要:

The magnetic flux dynamics of type-II superconductors within the critical state regime is posed in a generalized framework, by using a variational theory supported by well established physical principles. The equivalence between the variational statement and more conventional treatments, based on the solution of the differential Maxwell equations together with appropriate conductivity laws is shown. Advantages of the variational method are emphasized, focusing on its numerical performance, that allows to explore new physical scenarios. In particular, we present the extension of the so-called double critical state model to three dimensional configurations in which only flux transport (T-states), cutting (C-states) or both mechanisms (CT-states) occur. The theory is applied to several problems. First, we show the features of the transition from T to CT states. Second, we give a generalized expression for the flux cutting threshold in 3-D and show its relevance in the slab geometry. In addition, several models that allow to treat flux depinning and cutting mechanisms are compared. Finally, the longitudinal transport problem (current is applied parallel to the external magnetic field) is analyzed both under T and CT conditions. The complex interaction between shielding and transport is solved.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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