Contribution of the imaginary part of the superconducting gap energy on the SIS tunneling current

✍ Scribed by T. Noguchi; T. Suzuki; A. Endo; T. Tamura

• Book ID: 104084099
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 305 KB
• Volume: 469
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2009.05.218

✦ Synopsis

The dc I-V characteristics of Nb/AlÁAlO x /Nb SIS junctions are numerically investigated taking into account the broadening of quasiparticle density of states for Nb. It is demonstrated that calculated dc I-V curves agree well with those of Nb/AlÁAlO x /Nb SIS junctions measured at 4.2 K. It is also found that the subgap current is strongly dependent on bias voltage unlike the prediction of the BCS tunneling theory. It is also interesting to note that the decrease of a subgap current always saturates at a certain temperature when the temperature goes down. These predictions on the subgap current at low temperatures are consistent with the behavior of the subgap current of SIS junctions.