Electronic structure of Ca_1−xSr_xVO₃: a tale of two energy scales

Abstract

We investigate the electronic structure of Ca_1−xSr_xVO₃ using photoemission spectroscopy. Core level spectra establish an electronic phase separation at the surface, leading to a distinctly different surface electronic structure compared to the bulk. Analysis of the photoemission spectra of this system allowed us to separate the surface and bulk contributions. These results help us to understand properties related to two vastly differing energy scales, namely the low-energy scale of thermal excitations ( ~k_BT) and the high-energy scale related to Coulomb and other electronic interactions.