A Unified and Asymptotically Exact Theory of Superconductivity from Weak to Strong Coupling in an Electron–Phonon Model

2005 ◽  
Vol 139 (3-4) ◽  
pp. 419-428 ◽  
Author(s):  
Lei Sun ◽  
Xianxi Dai ◽  
Jixin Dai
Keyword(s):  
Strong Coupling ◽  
Exact Theory ◽  
Theory Of Superconductivity ◽  
Phonon Model

scholarly journals STRONG COUPLING THEORY OF IMPURE SUPERCONDUCTORS: REAL SPACE FORMALISM

1996 ◽  
Vol 10 (08) ◽  
pp. 353-358 ◽  
Author(s):  
YONG-JIHN KIM
Keyword(s):  
Transition Temperature ◽  
Strong Coupling ◽  
Real Space ◽  
The Self ◽  
Coupling Theory ◽  
Strong Coupling Theory ◽  
Nonmagnetic Impurities ◽  
Space Formalism ◽  
Self Consistency ◽  
Phonon Model

In the electron–phonon model, the influence of nonmagnetic impurities on the transition temperature of superconductors is revisited. Anderson’s pairing condition between time-reversed eigenstate pairs is derived from the physical constraint of the Anomalous Green’s function. After this pairing condition is incorporated into the self-consistency equation, one may find that the phonon-mediated interaction decreases exponentially by localization.

scholarly journals Exact Treatment of Bardeen's Theory of Superconductivity in the Strong Coupling Limit

1958 ◽  
Vol 19 (5) ◽  
pp. 597-598 ◽  
Author(s):  
Yasushi Wada ◽  
Fumihiko Takano ◽  
Nobuyuki Fukuda
Keyword(s):  
Strong Coupling ◽  
Strong Coupling Limit ◽  
Theory Of Superconductivity

AN APPLICATION OF THIRD FORMALISM OF QUANTUM STATISTICS AND A DIAGONALIZATION THEOREM IN ASYMPTOTIC EXACT THEORY OF SUPERCONDUCTIVITY

2005 ◽  
Vol 19 (01n03) ◽  
pp. 13-15
Author(s):  
LEI SUN ◽  
JIPING YE ◽  
XIANXI DAI ◽  
JIXIN DAI
Keyword(s):  
Perturbation Theory ◽  
Finite Order ◽  
Strong Coupling ◽  
Weak Coupling ◽  
Coupling Parameter ◽  
Quantum Statistics ◽  
Variation Method ◽  
The Third ◽  
Theory Of Superconductivity ◽  
Good Agreement

Starting from an electron-phonon interacting model, by means of the third formalism of quantum statistics, and with the aid of a diagonalization theorem, the Tc of superconductors from weak coupling to strong coupling cases are studied in a unified way. Our results are comparable with those of McMillan's theory, (which is valid up to the electron-phonon (e-ph) coupling parameter λ~1, a good agreement is shown for λ<1.3) and the Allen and Dynes's theory. Especially our results are very close to those of Hg spectrum with λ~2.0 and some strong coupling compounds. The theory is exact in the thermodynamic limit, without introducing variation method, the compensation of the dangerous diagrams in finite order in perturbation theory, abnormal green's function etc.

Sign in / Sign up

Export Citation Format

Share Document