Fig. 2

Strain-dependence and oxygen-dependence of the electronic structure. a Carrier density modulation determined at 50 K from Hall measurements from strained films grown on LSAO and LAO (closed circles) and partially relaxed films grown on LSAT and STO (open circles) to achieve different non-0% strain values. Gradual relaxation of tensile strain increases the hole carriers, approaching values that are similar to both strained and relaxed films under compressive strain. b Thickness-dependent XAS of the O K edge pre-peak region from strained (20 nm in thickness) and relaxed (125 nm) films (0% strain). The shift in spectral weight from peak A to peak B in strained films indicates hole depletion for tensile-strained films, which is not shown for the relaxed films on the same substrate. c, d Polarized XAS spectra of Cu L₃ edge for the same set of films measured in b, where E⊥ab (lines) and E∥ab (symbols) are the electric field oriented with respect to the \(3d_{z^2 - r^2}\) and \(3d_{x^2 - y^2}\) orbitals as schematically shown in the inset