Nonequilibrium quasiparticle and phonon dynamics in superconductors
Three problems concerning nonequilibrium phenomena in superconductors are discussed in this thesis. A theoretical treatment of the lifetimes of quasiparticles and phonons in low-energy states is given which relates the quasiparticle lifetimes to the low-frequency behavior of ..cap alpha../sup 2/(..cap omega..)F(..cap omega..) and shows the phonon lifetimes to depend on ..cap alpha../sup 2/(..cap omega..). Values for these lifetimes for a variety of superconductors in the dirty limit are obtained using tunneling and neutron-scattering data. Implications bearing on nonequilibrium phenomena are shown to be important in the two experimental studies discussed. A short discussion of the acoustic coupling of thin superconducting films prefaces an explanation of how a project designed to study this problem led to the discovery of a previously undetected effect: an inhomogeneous excess quasiparticle density in a photoexcited superconducting tunnel junction. Preliminary results of another study using the double-junction geometry are given in which direct experimental information on the form of the steady-state quasiparticle energy distribution is obtained for the first time.
- Research Organization:
- Pennsylvania Univ., Philadelphia (USA)
- OSTI ID:
- 6258136
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360104 -- Metals & Alloys-- Physical Properties
656101* -- Solid State Physics-- Superconductivity-- General Theory-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BISMUTH COMPOUNDS
CHALCOGENIDES
ELEMENTS
FILMS
LEAD COMPOUNDS
LIFETIME
METALS
OXIDES
OXYGEN COMPOUNDS
PHONONS
QUASI PARTICLES
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
TUNNEL EFFECT