Phase Separation of Superconducting Phases in the Penson–Kolb–Hubbard Model

Konrad Jerzy Kapcia, Wojciech Robert Czart, Andrzej Ptok
2016 Journal of the Physical Society of Japan  
In this paper we determine the phase diagrams (for T=0 as well as T>0) of the Penson-Kolb-Hubbard model for two dimensional square lattice within Hartree-Fock mean-field theory focusing on investigation of superconducting phases and possibility of the occurrence of the phase separation. We obtain that the phase separation, which is a state of coexistence of two different superconducting phases (with s-wave and η-wave symmetries), occurs in define range of the electron concentration. In
more » ... increasing temperature can change the symmetry of the superconducting order parameter (from η-wave into s-wave). The system considered exhibits also an interesting multicritical behaviour including bicritical points.
doi:10.7566/jpsj.85.044708 fatcat:jwqvwjpeqrddra6vrel6f25vlu