We have investigated the low-energy electronic structure of the heavy-fermion superconductor ${\text{CeCoIn}}_5$ by angle-resolved photoemission and band-structure calculations. We measured the Fermi surface and energy distribution maps along the high-symmetry directions at $h\nu =100\text{eV}$ and $T=25\text{K}$. The compound has quasi-two-dimensional Fermi-surface sheets centered at the $M\text{−}A$ line of the Brillouin zone. The band-structure calculations have been carried out within the local-density approximation where the $4f$ electrons have been treated either localized or itinerant. We discuss the comparison to the experimental data and the implications for the nature of the $4f$ electrons at the given temperature.

• Received 17 July 2008

DOI:https://doi.org/10.1103/PhysRevB.79.075104