Pseudogap and high-temperature superconductivity from weak to strong coupling. Towards a quantitative theory (Review Article) (original) (raw)
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Physical Review B, 2006
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Philosophical Magazine, 2014
We briefly overview the importance of Hubbard and Anderson-lattice models as applied to explanation of high-temperature and heavy-fermion superconductivity. Application of the models during the last two decades provided an explanation of the paired states in correlated fermion systems and thus extended essentially their earlier usage to the description of itinerant magnetism, fluctuating valence, and the metal-insulator transition. In second part, we also present some of the new results concerning the unconventional superconductivity and obtained very recently in our group. A comparison with experiment is also discussed, but the main emphasis is put on rationalization of the superconducting properties of those materials within the real-space pairing mechanism based on either kinetic exchange and/or Kondo-type interaction combined with the electron correlation effects.
Pseudogap transition within the superconducting phase in the three-band Hubbard model
2019
The onset of the pseudogap in high-T_c superconducting cuprates (HTSC) is marked by the T^* line in the doping-temperature phase diagram, which ends at a point p^* at zero temperature within the superconducting dome. There is no general consensus on how the pseudogap manifests itself within the superconducting phase. We use cluster dynamical mean field theory on a three-band Hubbard model for the HTSC to study the superconducting phase at T=0 K, obtained when doping the correlated insulator, for two different sets of band parameters and for several values of U. We observe a first-order transition within the superconducting phase, which we believe, marks the onset of the pseudogap. Further, we also observe that the d-wave node vanishes within the superconducting phase at low values of hole doping, lower than that at which the first-order transition occurs. Various aspects of the results and their implications are discussed.