Superconductivity in the pseudogap state in the hot spot model: The influence of impurities and the phase diagram

Abstract

We analyze the anomalies of superconducting state (both s and d-wave pairing) in the model of the pseudogap state induced by Heisenberg spin fluctuations of antiferromagnetic short -range order, and based on the scenario of strong scattering near the "hot spots" on the Fermi surface. We present microscopic derivation of Ginzburg -Landau expansion, taking into account all Feynman graphs of perturbation theory for electron interaction with fluctuations of short -range order and in the "ladder" approximation for electron scattering by normal (nonmagnetic) impurities. We determine the dependence of superconducting critical temperature Tc and other characteristics of a superconductor on the parameters of the pseudogap and impurity scattering. It is shown that within this model it is possible to explain the typical phase diagram of high -temperature superconductors.

Pseudogaps: introducing the length scale into dynamical mean-field theory

“…Thus scattering by random impurities with pointlike potential V is easily taken into account in self-consistent Born approximation [14]. Then, in comparison with impurity-free case, we have just a substitution (renormalization): e e r e e h e n n n n…”