Unified electronic phase diagram for hole-doped high-Tccuprates

Abstract

We have analyzed various characteristic temperatures and energies of hole-doped high-${T}_{c}$ cuprates as a function of a dimensionless hole-doping concentration $({p}_{u})$. Entirely based on the experimental grounds, we construct a unified electronic phase diagram (UEPD), where three characteristic temperatures (${T}^{\ensuremath{\ast}}$'s) and their corresponding energies (${E}^{\ensuremath{\ast}}$'s) converge as ${p}_{u}$ increases in the underdoped regime. ${T}^{\ensuremath{\ast}}$'s and ${E}^{\ensuremath{\ast}}$'s merge together with the ${T}_{c}$ curve and $3.5{k}_{B}{T}_{c}$ curve at ${p}_{u}\ensuremath{\sim}1.1$ in the overdoped regime, respectively. They finally go to zero at ${p}_{u}\ensuremath{\sim}1.3$. The UEPD follows an asymmetric half-dome-shaped ${T}_{c}$ curve, in which ${T}_{c}$ appears at ${p}_{u}\ensuremath{\sim}0.4$, reaches a maximum at ${p}_{u}\ensuremath{\sim}1$, and rapidly goes to zero at ${p}_{u}\ensuremath{\sim}1.3$. The asymmetric half-dome-shaped ${T}_{c}$ curve is at odds with the well-known symmetric superconducting dome for ${\text{La}}_{2\ensuremath{-}x}{\text{Sr}}_{x}{\text{CuO}}_{4}$ (SrD-La214), in which two characteristic temperatures and energies converge as ${p}_{u}$ increases and merge together at ${p}_{u}\ensuremath{\sim}1.6$, where ${T}_{c}$ goes to zero. The UEPD clearly shows that pseudogap phase precedes and coexists with high temperature superconductivity in the underdoped and overdoped regimes, respectively. It is also clearly seen that the upper limit of high-${T}_{c}$ cuprate physics ends at a hole concentration that equals to 1.3 times the optimal doping concentration for almost all high-${T}_{c}$ cuprate materials and 1.6 times the optimal doping concentration for the SrD-La214. Our analysis strongly suggests that pseudogap is a precursor of high-${T}_{c}$ superconductivity, the observed quantum critical point inside the superconducting dome may be related to the end point of UEPD, and the normal state of the underdoped and overdoped high temperature superconductors cannot be regarded as a conventional Fermi liquid phase.