We report the hole doping dependencies of the pseudogap phase energy scale, $2\Delta_{ \rm PG}$, the anti-nodal (nodal) superconducting energy scales $2\Delta^{ AN}_{ \rm SC}$ ($2\Delta^{ N}_{ \rm SC}$) and the charge density wave energy scale, $2\Delta_{ \rm CDW}$. They have been extracted from the electronic Raman responses of distinct copper oxide families. For all the cuprates studied, we reveal universal doping dependencies which suggest that $2\Delta_{ \rm PG}$, $2\Delta^{ AN}_{ \rm SC}$ and $2\Delta_{ \rm CDW}$ are governed by common microscopic interactions and that these interactions become relevant well above the superconducting transition at $T_c$. In sharp contrast, $2\Delta^N_{ \rm SC}$ tracks the doping dependence of $T_c$, appearing to be controlled by a different kind of interactions than the energy scales above.
Categories: cond-mat.supr-con