2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16184Based on an improved SU(2) slave-boson approach showing coupling between the cha rge and spin degrees of freedom, we derive a phase diagram of high $T_c$ cuprate s which displays both the superconducting and pseudogap phases in the plane of t emperature vs. hole doping rate. It is shown that phase fluctuations in the order parameters results in a closer agreement with the observed phase diagram of an arch shape, by manifesting the p resence of an optimal doping rate.5 pages and 2 figuresSuperconductivityStrongly Correlated Electronstext