Nonequilibrium quasiparticle distribution of photon- and phonon-irradiated superconducting tin tunnel junctions from I-V curve measurements
Precision measurements were made of the current-voltage characteristics of superconducting tin tunnel junctions driven out of thermal equilibrium by optical radiation or broad-band low-energy phonons. Careful measurements of the characteristics at small biases reveal that irradiation by light and by low-energy phonons drive the superconducting tin into distinctly different equilibrium states. The measurements for the optical case agreed with earlier results by other workers. The author also used the coupled kinetic equations developed by Chang and Scalapino to calculate the effect that each of these types of radiation should have on the quasiparticle distribution function in the superconductor. From the altered quasiparticle distribution and the usual tunneling integral, the effect of optical and phonon irradiation on the current-voltage characteristics was calculated. Calculated and measured results agreed for the light case, however, calculations for the phonon case always predicted large currents at small bias voltages than were measured. The author believes that the calculations fail in the phonon case because an assumption made in the development of the kinetic equations was inappropriate for pure tin films. The kinetic equations were valid only for dirty superconductors.
- Research Organization:
- California Univ., Irvine (USA)
- OSTI ID:
- 5696242
- Country of Publication:
- United States
- Language:
- English
Similar Records
Quasiparticle recombination time in superconducting lead and the quasiparticle nonequilibrium energy distribution of optically perturbed tin superconductors
Nonequilibrium superconductivity in spin-polarized superconducting tunneling junctions
Related Subjects
360104 -- Metals & Alloys-- Physical Properties
420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DISTRIBUTION
ELECTRICAL PROPERTIES
ELEMENTS
EQUILIBRIUM
JUNCTIONS
METALS
PHYSICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
QUASI PARTICLES
RADIATION EFFECTS
SUPERCONDUCTING JUNCTIONS
TIN
TUNNEL EFFECT