Magnetic interactions at the nanoscale in trilayer titanates LaTiO$_3$/SrTiO$_3$/YTiO$_3$

Abstract

We report on the phase diagram of competing magnetic interactions at nanoscale in engineered ultra-thin trilayer heterostructures of LaTiO3/SrTiO3/YTiO3, in which the interfacial inversion symmetry is explicitly broken. Combined atomic layer resolved scanning transmission electron microscopy with electron energy loss spectroscopy and electrical transport have confirmed the formation of a spatially separated two-dimensional electron liquid and high density two-dimensional localized magnetic moments at the LaTiO3/SrTiO3 and SrTiO3/YTiO3 interfaces, respectively. Resonant soft X-ray linear dichroism spectroscopy has demonstrated the presence of orbital polarization of the conductive LaTiO3/SrTiO3 and localized SrTiO3/YTiO3 electrons. Our results provide a route with prospects for exploring new magnetic interfaces, designing tunable two-dimensional d-electron Kondo lattice, and potential spin Hall applications.