We use angle-resolved photoemission spectroscopy (ARPES) to investigate the electronic properties of the newly discovered oxypnictide superconductor, NdFeAsO_{1-x}F_x. We find a well-defined Fermi surface that consists of a large hole pocket at the Brillouin zone center and a smaller electron pocket in each corner of the Brillouin zone. The overall location and shape of the Fermi surface agrees reasonably well with calculations. The band dispersion is quite complicated with many flat bands located just below the chemical potential. We observe a superconducting gap of 20 meV, which indicates that this system is in the strong coupling regime. The emergence of a coherent peak below the critical temperature Tc and diminished spectral weight at the chemical potential above Tc closely resembles the spectral characteristics of the cuprates.
@article{arxiv.0806.2147,
title = {Fermi surface and strong coupling superconductivity in single crystal NdFeAsO_{1-x}F_x},
author = {C. Liu and T. Kondo and M. E. Tillman and R. Gordon and G. D. Samolyuk and Y. Lee and C. Martin and J. L. McChesney and S. Bud'ko and M. A. Tanatar and E. Rotenberg and P. C. Canfield and R. Prozorov and B. N. Harmon and A. Kaminski},
journal= {arXiv preprint arXiv:0806.2147},
year = {2008}
}