Electronic structure of Ca1-xSrxVO3: A tale of two energy scales

We investigate the electronic structure of Ca1-xSrxVO3 using photoemission spectroscopy. Core level spectra establish an electronic phase separation a t the surface, leading to a distinctly different surface electronic structu re compared to the bulk. Analysis of the photoemission spectra of this syst em allowed us to separate the surface and bulk contributions. These results help us to understand properties related to two vastly differing energy sc ales, namely the low-energy scale of thermal excitations (similar tok(B)T) and the high-energy scale related to Coulomb and other electronic interacti ons.