Pseudogap and Superconducting Gap in Y-123: A Raman Study

TL;DR

This Raman study investigates the electronic properties of Y-123 across different doping levels, revealing the pseudogap's persistence above Tc and its relation to the superconducting gap, with implications for high-temperature superconductivity.

Contribution

It provides a detailed analysis of the pseudogap and superconducting gap in Y-123 using Raman spectroscopy and a memory function approach, highlighting their doping and temperature dependence.

Findings

Loss of spectral weight between Tc and T* at all doping levels

Pseudogap temperature T* is consistent with other experiments

Superconducting gap scales with Tc and depends on doping

Abstract

We present results of electronic Raman-scattering experiments in differently doped Y-123. In B2g symmetry, an analysis of the data in terms of a memory function approach is presented and dynamical relaxation rates $\Gamma(\omega,T)$ and mass-enhancement factors $1+\lambda(\omega,T)$ for the carriers are obtained. Starting from temperatures T > 180K, $\Gamma(\omega,T)$ and $1+\lambda(\omega,T)$ are extrapolated to lower temperatures and used to re-calculate Raman spectra. By comparison with our data, we find a loss of spectral weight between Tc < T < T* at all doping levels x. T* is comparable to the pseudogap temperature found in other experiments. Below Tc, the superconducting gap is observed. It depends on x and scales with Tc whereas the energy scale of the pseudogap remains the same.