High Tc Superconductor-Half metallic ferromagnet planar devices*

Superconducting spintronics is an emergent field where the interfacial interactions between superconductors (S) and ferromagnets (F) are crucial. These interactions can give rise to equal-spin triplet Cooper pairs, thereby opening the door to coherent, dissipationless spin transport. In this scenario, the case of high-temperature d-wave superconductors (e.g. YBa₂Cu₃O₇) combined with half-metal ferromagnets (e.g. La_0.7Sr_0.3MnO₃) is especially interesting. One of the challenges specific to those materials is the fabrication of nanoscale planar devices in which multiple S/F interfaces can be concatenated and electrically sensed individually. The difficulty comes from the fact that complex-oxides are often incompatible with many of the bottom-up nanofabrication approaches that are standard with metals. We will describe here various top-bottom approaches we have developed ad hoc to fabricate oxide planar S/F nanodevices, which are a combination of Pulsed Laser Deposition, Electron Beam Lithography and Ion Beam Etching. We will also present temperature-dependent magnetotransport measurements performed to characterize their superconducting and magnetic properties.