SISIS结中的电子对隧道效应的某些详细的分析和计算结果

The detail in the analysis and calculation on the tunnelling effect of Cooper pair in SISIS structure

采用Feynman方法分析了超导体-弱连接-超导体-弱连接-超导体结构(SISIS结)中的电子对隧道效应,得到了描述该效应的基本方程组.当两个弱连接结区处于零电压状态时,忽略弱连接结区的电容和电感(如超导桥和点接触的情况),得到了该方程组的严格解.结果表明,在没有任何外部因素(如外电压、外磁场等)影响时,完全由于SISIS结内部的电子对隧道效应,在SISIS结中会出现交流电,这种交变电流用椭圆函数表示.本文给出了这些结论的详细分析和计算结果.通过进一步的讨论还指出,在SISIS结中,并不会伴随着这种用椭圆函数表示的振荡电流的出现而发出电磁辐射.

The tunneling effect of the Cooper pairs in a SuperconductorInsulatorSuperconductorInsulatorSuperconductor(SISIS) structure is analyzed by Feynmanlike method, and the equations describing the electric current are obtained. For the case when both junctions are in the zero voltage state, while the capacitance and the inductance of both junctions are ignored (such as superconducting bridge and superconducting point contact), the exact solution of the equations is obtained. It is found that, because of the tunneling effect of the Cooper pairs, an alternating current exists which can be expressed by an elliptic function. The detail in the analysis and calculation on above results are given in this paper. And then, on second thoughts, the conclusion that the SISIS can not emit electromagnetic radiation when both junctions are in the zero voltage state, though an alternating current exists, is pointed out.