Magnetism and electronic structure of ($001$)- and ($111$)-oriented LaTiO$_3$ bilayers sandwiched in LaScO$_3$ barriers

TL;DR

This study uses density functional theory to analyze how the orientation of LaTiO$_3$ bilayers within LaScO$_3$ barriers influences their magnetic and electronic properties, revealing orientation-dependent electronic structure changes.

Contribution

It provides the first detailed comparison of ($001$) and ($111$)-oriented LaTiO$_3$ bilayers' magnetic and electronic structures using first-principles calculations.

Findings

Both orientations exhibit G-type antiferromagnetism.

The ($111$) orientation shows nearly flat Ti bands.

Electronic structure changes impact magnetic exchange interactions.

Abstract

In this study, the magnetism and electronic structure of LaTiO$_3$ bilayers along both the ($001$) and ($111$) orientations are calculated using the density functional theory. The band insulator LaScO$_3$ is chosen as the barrier layer and substrate to obtain the isolating LaTiO$_3$ bilayer. For both the ($001$)- and ($111$)-oriented cases, LaTiO$_3$ demonstrates the G-type antiferromagnetism as the ground state, similar to the bulk material. However, the electronic structure is significantly changed. The occupied bands of Ti are much narrower in the ($111$) case, giving a nearly flat band. As a result, the exchange coupling between nearest-neighbor Ti ions are reformed in these superlattices, which will affect the N\'{e}el temperature significantly.