Raman scattering cross sections depend on photon polarization. In the cuprates nodal and antinodal directions are weighted more strongly in B2g and B1g symmetry, respectively. On the other hand in angle-resolved photoemission spectroscopy (ARPES), electronic properties are measured along well-defined directions in momentum space rather than their weighted averages. In contrast, the optical conductivity involves a momentum average over the entire Brillouin zone. Newly measured Raman response data on high-quality Bi2Sr2CaCu2O8+δ single crystals up to high energies have been inverted using a modified maximum entropy inversion technique to extract from B1g and B2g Raman data corresponding electron-boson spectral densities (glue) are compared to the results obtained with known ARPES and optical inversions. We find that the B2g spectrum agrees qualitatively with nodal direction ARPES while the B1g looks more like the optical spectrum. A large peak around 30−40meV in B1g, much less prominent in B2g, is taken as support for the importance of (π,π) scattering at this frequency.
@article{arxiv.1009.1085,
title = {Electron-boson glue function derived from electronic Raman scattering},
author = {B. Muschler and W. Prestel and E. Schachinger and J. P. Carbotte and R. Hackl and Shimpei Ono and Yoichi Ando},
journal= {arXiv preprint arXiv:1009.1085},
year = {2015}
}