Origin of Strange Metallic Phase in Cuprate Superconductors

The origin of strange metallic phase is shown to exist due to these two conditions: (i) the electrons are strongly correlated such that there are neither band nor Mott–Hubbard gaps, and (ii) the electronic energy levels are crossed in such a way that there is an electronic energy gap between two energy levels associated with two different wave functions. The theory is also exploited to explain (i) the upward- and downward-shifts in the T-linear resistivity curves, and (ii) the spectral weight transfer observed in the soft X-ray absorption spectroscopic measurements of the La–Sr–Cu–O Mott insulator.