Microwave Photon Interaction with Superconducting Tunneling Currents
- 10 July 1967
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 159 (2), 374-382
- https://doi.org/10.1103/physrev.159.374
Abstract
The photon-assisted tunneling, originally observed by Dayem and Martin, has been remeasured for Al-In junctions and extended to Sn-Pb junctions. Particular attention has been devoted to obtaining detailed quantitative measurements of the current and the conductance versus voltage and for various microwave power levels. In addition to the steps in the tunneling current at observed by Dayem and Martin, we have observed an additional set at . We can conclude that the phase shift in peak position above the tunneling edge is from an almost exact superposition of these two sets of peaks, a consequence of the near coincidence of the microwave photon energy and one-half the energy gap of indium. A detailed comparison of our results with the theory of Tien and Gordon gives good agreement as to peak positions and shapes while the dependence of peak amplitude on microwave power level is poor, particularly at higher power levels. We have extended the Tien and Gordon theory to provide for a modulation of the density of states in both superconductors and have recalculated the tunneling current. The agreement with experiment is good, in particular, the nonvanishing of the conductance for any value of the microwave power is accounted for.
Keywords
This publication has 12 references indexed in Scilit:
- Tunneling Induced by Longitudinal Microwave Phonons in Al-Pb, Al-Sn, and Pb-Pb Superconducting DiodesPhysical Review B, 1966
- Nonlinear Self-Coupling of Josephson Radiation in Superconducting Tunnel JunctionsPhysical Review B, 1966
- Supercurrents through barriersAdvances in Physics, 1965
- Image of the Phonon Spectrum in the Tunneling Characteristic Between SuperconductorsPhysical Review Letters, 1963
- Multiphoton Process Observed in the Interaction of Microwave Fields with the Tunneling between Superconductor FilmsPhysical Review B, 1963
- Multiphonon Effects in Tunnelling Between Metals and SuperconductorsPhysical Review Letters, 1962
- Tunneling into Superconductors at Temperatures below 1°KPhysical Review B, 1962
- Quantum Interaction of Microwave Radiation with Tunneling Between SuperconductorsPhysical Review Letters, 1962
- Energy Gap in Superconductors Measured by Electron TunnelingPhysical Review Letters, 1960
- Theory of SuperconductivityPhysical Review B, 1957