Interplay of Jahn-Teller Distortion, Spin Density Wave and Superconductivity in Cuprates

The pairing mechanism and a definite origin of the pseudo gap are not clear till yet. In this communication, we report a microscopic theoretical model of the interplay of band Jahn-Teller (BJT) distortion, spin density wave (SDW) and superconductivity (SC) in high-Tc copper oxide superconductors. In under doped region, the long range antiferromagnetic order is destroyed to give rise to the SOW state arising due to Fermi surface instability. For suitable doping concentrations, superconductivity appears in the system giving highest To at optimal doping. Due to partial filling of the copper 3d electrons and doping, BJT distortion appears in the system. The BJT is treated here as a pseudogap which co-exists with superconductivity and extends to the normal phase. The BJT distortion, SOW and SC order parameters coexist and compete strongly with each other. These three temperature dependent order parameters are calculated by Green's function technique from the model Hamiltonian and solved self-consistently to investigate their interplay.