Fig. 3
From: A unified form of low-energy nodal electronic interactions in hole-doped cuprate superconductors
Theoretical plots of the imaginary part of the self energy for different doping regimes (red curves) for T = 100 K, β = π, λ = 0.5 and Γ0 = 0. a In the extreme heavily overdoped (HOD) case (α = 1) the system behaves as a normal Fermi liquid with a ω2 dependence. b In the optimally-doped case (α = 0.5) the system can be approximated as having a ω2 dependence at low ω and linear at high ω. c In the underdoped case (α = 0.25) the system has an unusual s-curve ω dependence that shows a concave-up ω2 dependence at low energies and a concave-down form at higher energy.
