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

TL;DR

This study investigates the magnetic interactions at the nanoscale in engineered trilayer titanate heterostructures, revealing spatially separated electron liquids and localized magnetic moments, with implications for novel magnetic interfaces and spintronic applications.

Contribution

It provides detailed experimental insights into magnetic phase behavior and orbital polarization in LaTiO₃/SrTiO₃/YTiO₃ heterostructures, a novel nanoscale magnetic system.

Findings

Confirmed formation of 2D electron liquid and localized magnetic moments at interfaces.

Demonstrated orbital polarization of electrons at interfaces.

Identified potential for tunable magnetic and spintronic devices.

Abstract

We report on the phase diagram of competing magnetic interactions at nanoscale in engineered ultra-thin trilayer heterostructures of LaTiO$_{3}$/SrTiO$_{3}$/YTiO$_{3}$, 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 LaTiO$_3$/SrTiO$_3$ and SrTiO$_3$/YTiO$_3$ interfaces, respectively. Resonant soft X-ray linear dichroism spectroscopy has demonstrated the presence of orbital polarization of the conductive LaTiO$_3$/SrTiO$_3$ and localized SrTiO$_3$/YTiO$_3$ 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.