Abstract

A method for calculating the critical state of inhomogeneous superconducting films using the Ginzburg–Landau (GL) theory is proposed. From the condition of minimizing the functional of the GL free energy, a system of equations describing the superconducting state of an inhomogeneous plate is derived. The dependences of the critical current of the plate on the external magnetic field are numerically calculated. It is shown that the critical current in a zero external magnetic field decreases with increasing degree of film inhomogeneity, while the critical magnetic field (at a zero transport current) increases. An analysis of the calculated dependences of the product of the critical current and the external magnetic field (an analogue of the volume pinning force) of superconducting films on the external magnetic field shows that the maximum of this value shifts to stronger fields with increasing degree of inhomogeneity, i.e., an increase in inhomogeneity leads to an increase in the pinning force.

中文翻译：

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用Ginzburg–Landau理论计算非均匀超导薄膜的关键参数的某些特征

摘要

提出了一种使用金兹堡-朗道（GL）理论计算非均匀超导膜的临界状态的方法。从最小化GL自由能的功能的条件出发，得出了描述非均质板超导状态的方程组。通过数值计算板的临界电流对外部磁场的依赖性。结果表明，在零外部磁场中的临界电流随着薄膜不均匀程度的增加而减小，而临界磁场（在零传输电流下）则增大。