T-dependent f-states in CeRhIn₅

CeRhIn₅, an antiferromagnet below 3.8K, is considered to exhibit fully localized Ce 4f behavior based on agreement of dHvA orbit sizes of α and β Fermi surface (FS) sheets to non-f LaRhIn₅ dHvA and to f-localized DFT calculations. Consistent with dHvA, we find using f-resonant angle-resolved photoemission (ARPES) negligible signatures of f-d hybridization at E_F for the α and β bands. However, contrary to the fully localized scenario, strong Kondo-like Ce 4f spectral weight is found in a shallow electron band corresponding to the third γ FS sheet in CeRhIn₅. The Ce 4f amplitude exhibits log(T) dependence above 50K up to 200K, similar to previous T-dependent measurements for CeCoIn₅ [1], and a change in the shape of the γ FS between low and high T is detected. The origins of this momentum-dependent participation of Ce 4f weight in the Fermi surface is theoretically investigated using first principles dynamical mean field theory (DMFT) calculations. The effects of in-plane versus out-of-plane Ce-In f-p hybridization and flattening of the ground state f-orbital for CeRhIn₅ compared to CeCoIn₅ and CeIrIn₅ are discussed.
[1] S. Y. Jang et al., arXiv:1704.08247 (2017).