Abstract
Hybridization between electrons and conduction bands (c-f hybridization) is a driving force for many unusual phenomena. To provide insight into it, systematic studies of heavy fermion superconductor have been performed by angle-resolved photoemission spectroscopy (ARPES) in a large angular range at temperature of K. The used photon energy of 122 eV corresponds to Ce resonance. Calculations carried out with the relativistic multiple scattering Korringa-Kohn-Rostoker method and one-step model of photoemission yielded realistic simulation of the ARPES spectra, indicating that Ce-In surface termination prevails. Surface states, which have been identified in the calculations, contribute significantly to the spectra. Effects of the hybridization strongly depend on wave vector. They include a dispersion of heavy electrons and bands gaining -electron character when approaching Fermi energy. We have also observed a considerable variation of -electron spectral weight at , which is normally determined by both matrix element effects and wave vector dependent c-f hybridization. Fermi surface scans covering a few Brillouin zones revealed large matrix element effects. A symmetrization of experimental Fermi surface, which reduces matrix element contribution, yielded a specific variation of -electron enhanced spectral intensity at around and points. Tight-binding approximation calculations for Ce-In plane provided the same universal distribution of -electron density for a range of values of the parameters used in the model.
2 More- Received 17 December 2020
- Revised 21 July 2021
- Accepted 23 August 2021
DOI:https://doi.org/10.1103/PhysRevB.104.125104
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