Airy-function electron localization in the oxide superlattices

TL;DR

This study uses density-functional theory to reveal how electron states in oxide superlattices are confined by a wedge-shaped potential, leading to Airy-function localization, with magnetic properties depending on LaTiO3 layer thickness.

Contribution

It demonstrates the formation of Airy-function localized electron states in oxide superlattices due to Coulomb potential effects, providing new insights into their electronic structure.

Findings

Electron states are confined by a wedge-shaped Coulomb potential.

Airy-function localization of electrons is observed in the superlattices.

Magnetism varies with LaTiO3 layer thickness, showing suppression or recovery.

Abstract

Oxide superlattices and microstructures hold the promise for creating a new class of devices with unprecedented functionalities. Density-functional studies of the recently fabricated superlattices of lattice-matched perovskite titanates (SrTiO3)n/(LaTiO3)m reveal a classic wedge-shaped potential originating from the Coulomb potential of a charged sheet of La atoms. The potential in turn confines the electrons in the vicinity of the sheet, leading to an Airy-function localization of the electron states. Magnetism is suppressed for structures with a single LaTiO3 monolayer, while the bulk antiferromagnetism is recovered in the structures with a thicker LaTiO3, with a narrow transition region separating the magnetic LaTiO3 and the non-magnetic SrTiO3.