We investigated hole (Cd)- and electron (Sn)-doped CeCoIn5 (CeCo(In1−xTx)5 (T = Cd or Sn)) using infrared spectroscopy. Doping-dependent hybridization gap distribution functions were obtained from the optical conductivity spectra based on the periodic Anderson model formalism. The hybridization gap distribution exhibits two components: in-plane and out-of-plane hybridization gaps. The doping-dependent evolution of the two gaps indicated that the out-of-plane gap was more sensitive to doping. Furthermore, the magnetic optical resistivity exhibited a doping-dependent evolution of the f-electron amplitude. The two dopant types exhibited different physical properties depending on the level of doping. The Sn dopant increases the f-electron amplitude, whereas the Cd dopant does not affect the f-electron amplitude. Doping-dependent effective mass is peaked at pure (or undoped) CeCoIn5. Our spectroscopic results may help understand the doping-dependent electronic evolution of one of the canonical heavy fermion systems, CeCoIn5.
@article{arxiv.2509.19684,
title = {Hybridization gap and $f$-electron effect evolutions with Cd- and Sn-doping in CeCoIn$_5$ via infrared spectroscopy},
author = {Myounghoon Lee and Yu-Seong Seo and Seulki Roh and Seokbae Lee and Jihyun Kim and Tuson Park and Jungseek Hwang},
journal= {arXiv preprint arXiv:2509.19684},
year = {2025}
}