Strongly hybridized electronic structure of YbAl2: An angle-resolved photoemission study

TL;DR

This study uses angle-resolved photoemission spectroscopy to reveal the electronic structure and strong hybridization effects in YbAl2, a valence fluctuation system, aligning experimental results with theoretical models.

Contribution

It provides detailed experimental evidence of band hybridization in YbAl2 and links it to valence fluctuations, advancing understanding of correlated electron systems.

Findings

Strong hybridization between conduction and 4f bands identified

Small mass enhancement factor observed

High Kondo temperature consistent with thermodynamic data

Abstract

We report the electronic structure of a prototypical valence fluctuation system, YbAl2, using angle-resolved photoemission spectroscopy. The observed band dispersions and Fermi surfaces are well described in terms of band structure calculations based on local density approximation. Strong hybridization between the conduction and 4f bands is identified on the basis of the periodic Anderson model. The evaluated small mass enhancement factor and the high Kondo temperature qualitatively agree with those obtained from thermodynamic measurements. Such findings suggest that the strong hybridization suppresses band renormalization and is responsible for the valence fluctuations in YbAl2.