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 crystals¹ : 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 efficiency². 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 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.

1 Rodel et al, Adv. Mater. 28, 1976 (2016)
2 Vaz et al, Nature Mater. 18, 1187 (2019)