Singularities of phonon spectra of superconductors observed with point contacts: A theory for dirty S-N contacts

Journal Article · Fri Feb 01 04:00:00 EST 1991 · Journal of Superconductivity; (United States)

DOI:https://doi.org/10.1007/BF00618297· OSTI ID:7171114

Khlus, V A; Dyomin, A V ^[1]

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1. Inst. for Single Crystals, Kharkov (Russian Federation)

Nonlinearities in the conductance of point contacts between a superconductor and a normal metal are considered for applied voltages larger than the energy gap {Delta}. The voltage dependence of the conductance and the second derivative of the current-voltage characteristic, resulting from the local electron-phonon interaction in the contact region, are obtained for the case where electrons move diffusively through the contact, their mean free path being much shorter than the contact dimension d. The conductance nonlinear structure corresponding to peaks of te Eliashberg function is calculated for simple model examples. These results are valid when the inequality {lambda}d{sup 2}{Delta}/{Dirac h}D < 1 holds, where {lambda} is the electron-phonon coupling constant and D is the electron diffusion coefficient. The second derivative, d{sup 2}I/dV{sup 2}, is obtained for voltages near the values corresponding to Van Hove singularities of the phonon density of states.

• OSTI ID: 7171114
• Journal Information: Journal of Superconductivity; (United States), Journal Name: Journal of Superconductivity; (United States) Vol. 4:1; ISSN JOUSE; ISSN 0896-1107
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COUPLING
ELECTRIC CONDUCTIVITY
ELECTRIC CONTACTS
ELECTRIC POTENTIAL
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRON-PHONON COUPLING
ENERGY GAP
EQUIPMENT
GORKOV-ELIASHBERG THEORY
JUNCTIONS
NONLINEAR PROBLEMS
PHYSICAL PROPERTIES
SUPERCONDUCTING JUNCTIONS