圆对称环域Josephson隧道结的静态特性(Ⅰ)——准衍射现象和自场效应

本文研究了圆对称环域Josephson隧道结的静态特性。在环带宽度较窄的情形下,不计入自场,并考虑到外磁场在结区内的非均匀性,解析地得到了l_m与外磁场的l_H的关系。与典型的小结衍射图形所不同的是所有极小都不为零,表现出准衍射图形特征。在环带宽度较宽的情形下,对自场方程进行了数值计算,得到其与一般一维结不同的结特性。 关键词：

STATIC CHARACTERISTICS OF CIRCULAR SYMMETRIC ANNULAR JOSEPHSON JUNCTION (Ⅰ)——THE QUASI-DIFFRACTION CHARACTERISTIC AND THE SELF-FIELD EFFECTS

The static Josephson effects in the circular symmetric annular junctions are discussed in this paper. When the annular widths are smaller than λ_J, analytic solutions of magnetic field dependence of the maximum Josephson current I_m, are obtained. Because the external magnetic field is nonuniform distributed in the junctions, the minima of l_m are not equal to zero. These results exhibit a quasi-diffraction characteristic. When the annular widths are larger than λ_J, the numerical solutions of the self-field equations are obtained, which show the magnetic field dependence of the maximun Josephson current I_m and the current distribution. Due to the 2-dimensional character, the points of maximum of I_m are not on the axis where the external field is equal to zero in the plot of I_m vs. I_H.