Superconductivity in the pseudogap state in the hot-spot model: Ginzburg-Landau expansion

Journal of Experimental and Theoretical Physics (Impact Factor: 0.92). 01/2004; 98(4):748-759. DOI: 10.1134/1.1757675
Source: arXiv

ABSTRACT Peculiarities of the superconducting state (s and d pairing) are considered in the model of the pseudogap state induced by short-range order fluctuations of the dielectric (AFM
(SDW) or CDW) type, which is based on the model of the Fermi surface with “hot spots.” A microscopic derivation of the Ginzburg-Landau
expansion is given with allowance for all Feynman diagrams in perturbation theory in the electron interaction with short-range
order fluctuations responsible for strong scattering in the vicinity of hot spots. The superconducting transition temperature
is determined as a function of the effective pseudogap width and the correlation length of short-range order fluctuations.
Similar dependences are derived for the main parameters of a superconductor in the vicinity of the superconducting transition
temperature. It is shown, in particular, that the specific heat jump at the transition point is considerably suppressed upon
a transition to the pseudogap region on the phase diagram.

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