We present a model analysis for the current-voltage (I-V) characteristics of Josephson junctions having super-conductor-insulator-superconductor (SIS) structure. The numerical result for the Vm value, which is the product of the maximum supercurrent and the observed subgap resistance, shows a marked decrease with increasing junction critical current density (Jc). The marked decrease is independent of leak current. Increasing Jc reduces he junction capacitance CJ and enlarges the amplitude of the junction voltage oscillation. Nonlinearity of the quasiparticle resistance restricts the voltage oscillation amplitude to the gap voltage, which results in the rapid decrease of the Vm value. In this paper, we introduce a sinusoidal oscillation model for the junction voltage, and derive the approximated expressions for the Vm value. The model approximation results agree well with the numerical results.
|ジャーナル||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|出版ステータス||Published - 1997 1月|
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