Niobium nitride Josephson tunnel junctions with magnesium oxide barriers

Shoji, Akira; Aoyagi, Masahiro; Kosaka, Shin; Shinoki, Fujitoshi; Hayakawa, Hisao
June 1985
Applied Physics Letters;6/1/1985, Vol. 46 Issue 11, p1098
Academic Journal
Niobium nitride-niobium nitride Josephson tunnel junctions have been fabricated using amorphous magnesium oxide (a-MgO) films as barriers. These junctions have excellent tunneling characteristics. For example, a large gap voltage (Vg=5.1 mV), a large product of the maximum critical current and the normal tunneling resistance (IcRn=3.25 mV), and a small subgap leakage current (Vm=45 mV, measured at 3 mV) have been obtained for a NbN/a-MgO/NbN junction. The critical current of this junction remains finite up to 14.5 K.


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