About cookies on this site Our websites require some cookies to function properly (required). In addition, other cookies may be used with your consent to analyze site usage, improve the user experience and for advertising. For more information, please review your options. By visiting our website, you agree to our processing of information as described in IBM’sprivacy statement. To provide a smooth navigation, your cookie preferences will be shared across the IBM web domains listed here.
Publication
Applied Physics Letters
Paper
The subgap current in Nb/AlOx/Nb tunnel junctions
Abstract
We have measured the subgap current at 0.8 K in several hysteretic 1.5×1.6 and 2.6×2.6 μ m2 NbAlOxNb tunnel junctions. In zero magnetic field, the critical current Ic ∼8 μA and the subgap resistance R∼0.3 MΩ. When we apply a magnetic field, Ic can be as low as 1 nA, and R is larger than 1 GΩ. This means that in a superconducting qubit made using Nb tunnel junctions, the decoherence rate from the quasiparticle conductance may be as low as 1 (100 μs). © 2004 American Institute of Physics.