Energy Scales in the Raman spectrum of electrons and hole doped cuprates within competing scenarios

TL;DR

This paper investigates how the pseudogap and superconductivity competition affects the Raman spectra in electron- and hole-doped cuprates, explaining the differences in energy scales through Fermi surface truncation.

Contribution

It provides a comparative analysis of the Raman spectral features in electron- and hole-doped cuprates considering pseudogap effects and Fermi surface truncation.

Findings

Hole-doped cuprates show two energy scales in Raman spectra due to pseudogap-superconductivity competition.

Electron-doped cuprates exhibit a single energy scale with peaks at a few meV in both Raman channels.

Fermi surface truncation explains the difference in energy scales between electron- and hole-doped systems.

Abstract

Recent experiments in underdoped hole-doped cuprates have shown the presence of two energy scales in the Raman spectrum in the superconducting state. This feature has a natural explanation in some models in which pseudogap and superconductivity compete. In electron-doped cuprates antiferromagnetic correlations are believed to survive in the superconducting state, and to produce a pseudogap above the critical temperature. Contrary to hole-doped systems, in electron-doped compounds only one energy scale appear since the pair breaking Raman intensity peaks in both B$_{1g}$ (antinodal) and B$_{2g}$ (nodal) channels at a frequency of a few meV, typical of the superconducting order parameter. In this paper we analyze the different effect in the Raman spectrum of the competition between pseudogap and superconductivity in electron and hole-doped cuprates. The difference in energy scales in both systems is explained in terms of the different truncation of the Fermi surface induced by the pseudogap. For electron-doped cuprates we also analyze the spectrum with antiferromagnetism and a non-monotonic superconducting order parameter.