Pressure Evolution of X-ray Raman Spectra in a Novel Monoclinic V2O3 Metal

V2O3 is a prototypical metal-to-insulator transition system, where the transition always coincides with a corundum-to-monoclinic structural transition in temperature-dependent studies. However, recent pressure-dependent study demonstrates that the two transitions can be decoupled, showing a novel monoclinic metallic phase above a critical pressure Pc around 33 GPa. Here we study the corresponding pressure evolution of electronic structure with X-ray Raman scattering. The spectra do not exhibit any appreciable difference at low pressures, but broaden substantially across Pc. Multiplet calculations with additional screening channels from coherent quasiparticles indicate a weakened screening effect at high pressures. This could result from a decreased coherent quasiparticle strength due to enhanced electronic correlation, suggesting that V2O3 in the high-pressure monoclinic phase is a critical correlated metal on the verge of Mott- insulating behavior.