Anisotropic evolution of energy gap in Bi2212 superconductor

TL;DR

This paper analyzes how the energy gap in underdoped Bi2212 superconductors varies with temperature and doping, using a theoretical model that accurately reproduces experimental ARPES data and highlights the pseudogap phenomenon.

Contribution

It introduces a theoretical framework combining electron-phonon and electron-electron-phonon interactions to explain the anisotropic energy gap evolution in Bi2212.

Findings

Energy gap weakly depends on temperature

Energy gap strongly depends on doping level

Presence of a pseudogap above critical temperature

Abstract

We present a systematic analysis of the energy gap in underdoped Bi2212 superconductor as a function of temperature and hole doping level. Within the framework of the theoretical model containing the electron-phonon and electron-electron-phonon pairing mechanism, we reproduced the measurement results of modern ARPES experiments with very high accuracy. We showed that the energy-gap amplitude is very weakly dependent on the temperature but clearly dependent on the level of doping. The evidence for a non-zero energy gap above the critical temperature, referred to as a pseudogap, was also obtained.