Prediction of a spin-polarized two-dimensional electron gas at the LaAlO3/EuO(001) interface

TL;DR

First-principles calculations reveal a spin-polarized two-dimensional electron gas at the LaAlO3/EuO interface, driven by polar discontinuity and EuO's ferromagnetism, with potential applications in spintronics.

Contribution

This work predicts, using first-principles calculations, the formation of a spin-polarized 2DEG at the LaAlO3/EuO interface, highlighting a novel mechanism involving polar and ferromagnetic insulators.

Findings

A spin-polarized 2DEG exists at the LaAlO3/EuO interface.

The 2DEG is formed due to electron doping into Eu-5d conduction bands.

The 2DEG exhibits spin polarization below EuO's Curie temperature.

Abstract

First-principles calculations predict the existence of a spin-polarized two-dimensional electron gas (2DEG) at the LaO/EuO interface in a LaAlO3/EuO (001) heterostructure. This polar interface favors electron doping into the Eu-5d conduction bands resulting in a 2DEG formed at the interface. Due to the exchange splitting of the Eu-5d states the 2DEG is spin-polarized below the Curie temperature of EuO. The predicted mechanism for the formation of a spinpolarized 2DEG at the interface between polar and ferromagnetic insulators may provide a robust magnetism of the 2DEG which is interesting for spintronics applications.