The single-particle self-energy and fluctuation spectrum of slightly underdoped Bi2212 from ARPES experiment

We extract the single particle self-energy $\Sigma(\theta,\omega) $ and Eliashberg function $\alpha^2 F(\theta,\omega)$ of normal and superconducting state Bi2212 from ARPES experiments. The self-energies along the cuts at tilt angle $\theta$ were extracted by fitting ARPES momentum distribution curves. Then, using the extracted self-energy as input, the Eliashberg function is deduced by inverting the d- wave Eliashberg equation employing the adaptive maximum entropy method (MEM). The momentum dependence of self-energy was decomposed in terms of $\Sigma(\theta,\omega) = \Sigma_{0}(\omega) + \Sigma_{4}(\omega) cos4\theta $ at 16, 70, 80, 97, and 107 K. We will present the temperature evolution and momentum dependence of the deduced Eliashberg function and self-energy.