Theory of high-temperature superconductivity in doped polar insulators
Department of Physics, Loughborough University - Loughborough LE11 3TU, UK, EU
Accepted: 31 May 2011
Many high-temperature superconductors are highly polarizable ionic lattices where the Fröhlich electron-phonon interaction (EPI) with longitudinal optical phonons creates an effective attraction of doped carriers virtually equal to their Coulomb repulsion. The general multi-polaron theory is given with both interactions being strong compared with the carrier kinetic energy so that the conventional BCS-Eliashberg approximation is inapplicable. The many-electron system is described by the polaronic t-Jp Hamiltonian with reduced hopping integral, t, allowed double on-site occupancy, large phonon-induced antiferromagnetic exchange, Jp≫t, and a high-temperature superconducting state of small superlight bipolarons protected from clustering.
PACS: 71.38.-k – Polarons and electron-phonon interactions / 72.15.Jf – Thermoelectric and thermomagnetic effects / 74.72.-h – Cuprate superconductors
© EPLA, 2011