Influence of collective effects and the d-CDW on electronic Raman scattering in high-T$_c$ superconductors

TL;DR

This paper investigates how collective effects and the d-wave charge density wave influence electronic Raman scattering in high-temperature superconductors, highlighting the roles of different order parameters and their competition.

Contribution

It introduces a theoretical analysis within the t-J model showing how amplitude fluctuations of order parameters affect Raman spectra, supporting the two-order-parameter picture in underdoped cuprates.

Findings

A1g spectra dominated by superconducting order fluctuations

B1g spectra dominated by d-wave CDW fluctuations

B2g spectra show no collective effects, reflecting T_c doping dependence

Abstract

Electronic Raman scattering in high-T$_c$ superconductors is studied within the t-J model. It is shown that the A$_{1g}$ and B$_{1g}$ spectra are dominated by amplitude fluctuations of the superconducting and the d-wave CDW order parameters, respectively. The B$_{2g}$ spectrum contains no collective effects and its broad peak reflects vaguely the doping dependence of T$_c$, similarly to the pronounced peak in the A$_{1g}$ spectrum. The agreement of our theory with the experiment supports the picture of two different, competing order parameters in the underdoped regime of high-T$_c$ superconductors.