Superconductivity of repulsive particles
Lebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation
Antiferromagnetic correlations in superconducting
cuprates can lead to the mirror nesting of Fermi contour segments near saddle points of the electron spectrum and to a
logarithmic singularity of the scattering amplitude for a large
pair momentum. The Coulomb potential defined within a kinematically allowed region allows a negative eigenvalue, which provides superconducting pairing and weakly decaying, quasistationary, large-momentum pair states. The Ginzburg-Landau equations for the two-component superconducting order parameter provide pairs of coupled particles and pairs of
coupled orbital current circulations, which explains the fundamental cuprate properties such as strong and weak pseudogaps, the superconducting transition temperature, the diamagnetic pseudogap state, and details of the isotope effect. A quantum critical point and a transition of two superconducting phases, one of which displays superconductivity with current circulations, are predicted.