Local phonon model for strong-coupling superconductors

Thesis/Dissertation · Sun Jan 01 00:00:00 EST 1984

OSTI ID:5901521

Yu, C C

The A15 metals and other high transition temperature super-conductors have been an outstanding puzzle of solid state physics for decades. High temperature experimental data reveal anomalies in the fundamental electronic properties of these materials, implying strong electron-phonon coupling and large violations of such sacred principles as Migdal's theorem and Matthiesen's rule. Conventional theories fail to explain this behavior even qualitatively. A model is proposed in which a single atom interacts strongly with a Fermi gas of spinless electrons. It was found that the electrons provide an effective double well potential for the atom. The electron-phonon coupling ..lambda.. is renormalized downwards with decreasing temperature provided that ..lambda.. is large at high temperatures. The model is consistent with the experimental temperature dependence of the Pauli susceptibility and the resistivity as well as with the violation of Matthiessen's rule. It provides a possible explanation for why the observed martensitic transition is so small. It was found that the violation of Migdal's theorem implies time-retarded interactions between hops of the atom from one minimum of the double well to the other.

• Research Organization: Princeton Univ., NJ (USA)
• OSTI ID: 5901521
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
SUPERCONDUCTORS
STRONG-COUPLING MODEL
ELECTRONS
ERRORS
FERMI GAS
MATTHIESSEN RULE
MIGDAL THEORY
PHONONS
ELEMENTARY PARTICLES
FERMIONS
FLUIDS
GASES
LEPTONS
MATHEMATICAL MODELS
PARTICLE MODELS
QUASI PARTICLES
656101* - Solid State Physics- Superconductivity- General Theory- (-1987)