Angle-resolved photoemission spectroscopy study of the Möbius Kondo insulator candidate CeRhSb

The electronic structure of a Möbius Kondo insulator candidate of CeRhSb has been investigated by employing angle-resolved photoemission spectroscopy, density functional theory (DFT) band calculations, and dynamical mean-field theory (DMFT) band calculations. Fermi surfaces (FSs) and band structures are successfully measured for three orthogonal crystallographic directions. A sharp Ce 4f peak is observed at the Fermi level (EF), and its temperature (T) evolution agrees with that of the Ce 4f Kondo resonance. The metallic FSs are obtained for all three different (100), (010), and (001) planes. The Ce 4f FSs are described properly by the unfolded DFT calculations considering the reduced Ce-only unit cell. The T dependence of Ce 4f states as well as the dispersive coherent Ce 4f bands are described well by the DMFT calculations and reveal the anisotropic c−f hybridization. The photon energy dependence of the Fermi-edge states in CeRhSb reveals the three-dimensional character, consistent with the bulk states dispersing to EF over a larger energy scale rather than the predicted Möbius topological surface states.