Using methods made possible by recent advances in photoemission technology, we perform an indepth line shape analysis of the angle-resolved photoemission spectra of the electron doped (n-type) cuprate superconductor ${\mathrm{Nd}}_{1.85}{\mathrm{Ce}}_{0.15}{\mathrm{CuO}}_4.$ Unlike for the p-type materials, we only observe weak mass renormalizations near 50–70 meV. This may be indicative of smaller electron-phonon coupling or due to the masking effects of other interactions that make the electron-phonon coupling harder to detect. This latter scenario may suggest limitations of the spectral function analysis in extracting electronic self-energies when some of the interactions are highly momentum dependent.

• Received 9 December 2002

DOI:https://doi.org/10.1103/PhysRevB.68.064517