Abstract
We have examined the electronic structure of the heavy fermion in comparison with the superconductor by means of high-resolution photoelectron spectroscopy (PES) and resonant x-ray emission spectroscopy (RXES). The PES data are interpreted in light of the density of states calculated within the local density approximation plus the dynamical mean-field theory. Our analysis of the RXES data shows that the valence of Yb in is weakly fluctuating, indicating weak but finite hybridization, and decreases slightly with temperature. In contrast, the Yb valence in is nearly 3 and does not show any temperature dependence, suggesting that the Yb electrons are localized and the superconductivity is due to the Pd conduction electrons. The constant initial state spectra at the Yb resonance for clearly show resonant behavior for and antiresonance for , indicating that the and states are intimately correlated.
- Received 6 June 2012
DOI:https://doi.org/10.1103/PhysRevB.86.085137
©2012 American Physical Society