Exploration of interfacial conductivity and magnetism in manganite/cuprate heterostructures

Superconductivity emerging at the interface of heterostructures provides a unique platform to study and control superconductivity at the two-dimensional limit and offers a promising avenue for discovering new superconducting materials. By adjoining an undoped cuprate layer, such as La₂CuO₄ (LCO) and SrCuO₂(SCO), with a hole-doped La_1-xSr_xMnO₃(LSMO) layer, we systematically investigate the conductivity and magnetism of manganite/cuprate heterostructures while varying the LSMO doping level from 0.33 to 0.80 to tune LSMO from a ferromagnetic metal to an antiferromagnetic insulator. Driven by the difference in work functions, charges are transferred from the LSMO layer to the cuprate layer, thereby giving rise to a conducting interfacial layer when the LSMO layer is heavily doped. No signature of interface superconductivity is observed in any of the synthesized heterostructures, a behavior likely attributable to spin-polarized charge transfer and the competition between superconductivity and magnetism. Our findings provide valuable insights into the mechanism of interface superconductivity as well as guidelines for the search for emergent interfacial effects.