Detection of Spin Polarized Band in VO2/TiO2(001) Strained Films via Orbital Selective Constant Initial State Spectroscopy

The VO2 is a 3d1 electron system that undergoes a reversible metal-insulator transition (MIT) triggered by temperature and characterized by an interplay between orbital, charge and lattice degrees of freedom. The characterization of the MIT features are therefore extremely challenging and powerful investigation tools are required. In this work, we demonstrate how a combination of resonant photoemission and constant initial state (CIS) spectroscopy can be used as an orbital selective probe of the MIT studying three different VO2/TiO2(001) strained films. The CIS spectra of the V 3d and V 3p photo-electrons shows sensitivity to different orbital contribution and the presence of a spin polarized band close to the Fermi level.