Quasiparticle lifetimes and tunneling times in a superconductor-insulator-superconductor tunnel junction with spatially inhomogeneous electrodes

Journal Article · Sun May 01 00:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.12953· OSTI ID:5007663

Golubov, A A; Houwman, E P; Gijsbertsen, J G; Flokstra, J; Rogalla, H ^[1]; le Grand, J B; de Korte, P A.J. ^[2]

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1. University of Twente, Department of Applied Physics, P.O. Box 217, 7500 AE Enschede (Netherlands)
2. Laboratory for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

The low-energy quasiparticle scattering and recombination lifetimes for a proximity sandwich of two superconductors [ital S] and [ital S][prime] with different bulk energy gaps, are calculated as a function of the spatial coordinate and temperature. The spatial dependence of the order parameter and density of states are calculated on the basis of a microscopic model of the proximity effect, based on the Usadel equations, for dirty superconductors in thermal equilibrium. A zero boundary resistance between [ital S] and [ital S][prime] and a Boltzmann-like energy distribution of the excess quasiparticles are assumed. In the case of a small diffusion time constant an effective quasiparticle relaxation rate into and excitation rate out of the reduced gap region in the [ital SS][prime] sandwich are obtained as a function of (finite, but low) temperature and strength of the proximity effect, determined by the parameter [gamma][sub [ital m]], by averaging over the energies and positions of the quasiparticles. In the same way effective tunneling times for electrons and holes tunneling out of the trap in the [ital SS][prime] sandwich to the other electrode of an [ital SS][prime][ital IS][prime][prime][ital S] junction are determined as a function of temperature, voltage, and [gamma][sub [ital m]].

• OSTI ID: 5007663
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 49:18; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
SUPERCONDUCTING JUNCTIONS
PROXIMITY EFFECT
TUNNEL EFFECT
ELECTRODES
ELECTRONS
ENERGY GAP
ENERGY-LEVEL DENSITY
FLUCTUATIONS
HOLES
LIFETIME
ORDER PARAMETERS
RECOMBINATION
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0065-0273 K
TRAPPING
ELEMENTARY PARTICLES
FERMIONS
JUNCTIONS
LEPTONS
TEMPERATURE RANGE
VARIATIONS
665412* - Superconducting Devices- (1992-)