  The emergence of superconductivity in unconventional superconductors usually
accompanies the normal-state phases of pseudogap, strange metal and Fermi
liquid. It indicates these phases are strongly related to the superconducting
state and should be dominated by yet unclear mechanism of superconductivity.
Here, we propose a microscopic theory that, according to the coupling between
localized and extended states, the pairing electrons which leap on and off a
localized state result in superconducting instability. Two distinguishable
pairing gaps are observed in these states, one dominates the superconducting
temperature and another the temperature of a coherent pair confined at
localized area. The pairing correlation between these states results in four
phases. Their characteristics are manifested in universal Planckian-like
resistivity and unusual carrier distribution, as observed in recent
experiments.
