Exploring possible Fermi surface nesting and the nature of heavy quasiparticles in the spin-triplet superconductor candidate ${\mathrm{CeRh}}_2{\mathrm{As}}_2$

In this Letter, we investigate the electronic structure of a spin-triplet superconductor candidate ${\mathrm{CeRh}}_2{\mathrm{As}}_2$ using high-resolution angle-resolved photoemission spectroscopy and density functional theory calculations. Notably, possible Fermi surface nesting hints at connections to magnetic excitation or quadrupole density wave phenomena, elucidating the superconducting mechanisms. Measured band structures reveal primarily localized $4f$ electrons, with minor itinerant contributions. Additionally, a transition from localized to itinerant behavior and significant $c\text{−}f$ hybridization anisotropy underscore the role of $f$ electrons in shaping electronic properties. These findings deepen our understanding of ${\mathrm{CeRh}}_2{\mathrm{As}}_2$'s unconventional superconductivity and magnetism. Further exploration promises advances in superconductivity research.