The electronic structure of CeCoIn5 from angle-resolved photoemission spectroscopy II: Hybridization effects

TL;DR

This study uses angle-resolved photoemission spectroscopy to analyze the electronic structure and hybridization effects in the heavy fermion superconductor CeCoIn5, revealing temperature-dependent band behavior and spectral weight variations.

Contribution

It provides new insights into the hybridization effects and electronic structure of CeCoIn5 through detailed ARPES measurements and a two-level mixing model analysis.

Findings

Observation of temperature-dependent Fermi surface changes.

Detection of a flat f-derived band with k-dependent spectral weight.

Qualitative fit to a two-level mixing model from the Periodic Anderson Model.

Abstract

We have investigated the low-energy electronic structure of the heavy fermion superconductor CeCoIn5 by angle-resolved photoemission. We focus on the dispersion and the peak width of the prominent quasi-two-dimensional Fermi surface sheet at the corner of the Brillouin zone as a function of temperature along certain k-directions with a photon energy of hn = 100 eV. We find slight changes of the Fermi vector and an anomalous broadening of the peak width when the Fermi energy is approached. Additionally we performed resonant ARPES experiments with hn = 121 eV. A flat f-derived band is observed with a distinct temperature dependence and a k-dependent spectral weight. These results, including both off- and on-resonant measurements, fit qualitatively to a two level mixing model derived from the Periodic Anderson Model.