Figure 4: Theoretical results of electronic density and magnetisation at the LSCO/LSMO interface, and comparison with experimental results.

(a) Calculated 3d orbital occupation for Cu and Mn near the LSCO/LSMO type B interface (see Fig. 1), showing a partial filling of the Cu-$d_{x^2-y^2}$ states (normally approximately half filled), and a small reduction, at the interfacial CuO₂ plane only, of the number of electron in the Cu-$d_{3z^2-r^2}$ states. Similarly, the Mn atoms increase the electronic occupation next to the interface, so that an overall electron-rich region is created across the interface: these electrons are coming from the bulk of LSMO. (b) Calculated magnetisation profile along the c axis in the cuprate layer in proximity of the interface for different values of the external magnetic field and antiferromagnetic J_A=0.15 t (with t hopping integral). (c) Calculated total magnetisation of the cuprate layer as a function of the magnetic field for different values of J_A (black line and dash blue line), compared with the magnetic Cu spin moment determined with sum rules from the experimental XMCD spectra (red square). The error bars for the Cu spin moment indicate the minimum non-zero value detectable in our XMCD experiment.