Towards skyrmionic spin textures combined with SrTiO₃ two-dimensional electron gases

SrTiO₃ (STO) two-dimensional electron gases (2DEGs) can be formed by depositing reactive metals such as Al onto STO single crystals: the metal oxidizes, forming oxygen vacancies in the STO and thus doping it in electrons. Such 2DEGs can then be used to interconvert spin and charge currents with great efficiency. In this presentation we will show that the metal oxide (e.g. AlOx) thus formed can be combined with ferromagnetic and heavy-metal-based ultrathin films to generate various types of magnetization configurations with in-plane or out-of-plane anisotropy, depending on their relative thicknesses. For specific compositions, these multilayers harbor magnetic bubbles, as imaged by magnetic force microscopy and X-ray photoemission electron microscopy, that likely have a skyrmionic character, due to the expected Dzyaloshinskii-Moriya interaction caused by the strong broken inversion symmetry.