RELAXATION OSCILLATIONS IN JOSEPHSON JUNCTIONS.
Abstract
Investigation of the characteristics of Josephson tunneling in tin/tin oxide/tin junctions showed that pulse voltages with sharp rise times were being generated. Pulse amplitude across the junction remained constant and equal to the energy gap voltage V sub g, but pulse frequency could be changed over a 25:1 range by a change in bias voltage from 0 to an upper limit approximately equal to V sub g/2. The oscillation mechanism is that of switching between the pair-current state of the junction at V = 0 and the quasi-particle current state at V = V sub g. The external circuit maintains the switching cycle and determines the output frequency characteristics. Using the L/R time constant of the external circuit and the assumed basic dc I(V) curve of the junction in the absence of relaxation oscillations, calculations were made that accurately describe the observed dc I(V) curves, frequency, and waveforms, including their dependence on bias voltage and magnetic field. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1968
- Accession Number
- AD0670157
Entities
People
- Frank L. Vernon Jr.
- Robert J. Pedersen
Organizations
- The Aerospace Corporation