The quantum confinement of strongly correlated electrons in artificial structures provides a platform for studying the behavior of correlated Fermi-liquid states in reduced dimensions. We report the creation and control of two-dimensional electron-liquid states in ultrathin films of SrVO3 grown on Nb:SrTiO3 substrates, which are artificial oxide structures that can be varied in thickness
by single monolayers. Angle-resolved photoemission from the SrVO3/Nb:SrTiO3 samples shows metallic quantum well states that are adequately described by the well-known phase-shift quantization rule. The observed quantum well states in SrVO3 ultrathin films exhibit distinctive
features—such as orbital-selective quantization originating from the anisotropic orbital character
of the V 3d states and unusual band renormalization of the subbands near the Fermi level—that reflect complex interactions in the quantum well.