Optical Response for the d-density wave model

TL;DR

This paper calculates the optical and Raman responses of the d-density wave model to explain the pseudogap in high-temperature cuprates, revealing spectral weight transfer and temperature effects.

Contribution

It provides detailed theoretical predictions of optical and Raman responses in the d-density wave model, linking spectral features to the pseudogap phenomenon.

Findings

Optical spectral weight remains roughly constant across the pseudogap opening.

Spectral weight shifts from the Drude peak to interband transitions.

Temperature and scattering effects diminish the interband peak's prominence.

Abstract

We have calculated the optical conductivity and the Raman response for the d-density wave model, proposed as a possible explanation for the pseudogap seen in high Tc cuprates. The total optical spectral weight remains approximately constant on opening of the pseudogap for fixed temperature. This occurs because there is a transfer of weight from the Drude peak to interband transitions across the pseudogap. The interband peak in the optical conductivity is prominent but becomes progressively reduced with increasing temperature, with impurity scattering, which distributes it over a larger energy range, and with ineleastic scattering which can also shift its position, making it difficult to have a direct determination of the value of the pseudogap. Corresponding structure is seen in the optical scattering rate, but not necessarily at the same energies as in the conductivity.