Document Type
Article
Publication Date
1989
Abstract
The inverse ac Josephson effect occurs when a Josephson junction driven by a microwave source of frequency f produces constant‐voltage steps at integer multiples of h f/2e. For low‐leakage current hysteretic junctions driven at microwave frequencies below about 100 GHz, some of these steps can cross the zero dc bias current axis. These zero‐crossing steps allow modern series array voltage standards to operate without individually biasing the junctions in the array. We reexamine the theory behind these steps and show that they can exist at frequencies much higher than thought previously. The Riedel singularity in the supercurrent response allows this effect to exist even up to terahertz frequencies. We describe a set of analytical calculations which provide limits on the amount of rounding of the Riedel peak which can be permitted while still allowing these zero‐crossing steps to occur. We also discuss practical considerations such as microwave power levels required and parameters for device fabrication. This analysis is supported by numerical frequency‐domain computations and time‐domain simulations for a number of realistic I‐V curves with rounded Riedel singularities and with quasiparticle subgap leakage currents.
DOI
10.1063/1.342768
Recommended Citation
W. C. Danchi, W. J. Golightly and E. C. Sutton. Inverse Ac Josephson Effect at Terahertz Frequencies. J. Appl. Phys. 65, 2772 (1989).
Comments
Copyright 1989 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.
The following article appeared in W. C. Danchi, W. J. Golightly and E. C. Sutton. Inverse Ac Josephson Effect at Terahertz Frequencies. J. Appl. Phys. 65, 2772 (1989). and may be found at http://dx.doi.org/10.1063/1.342768.