Two Dimensional Spin-Polarized Electron Gas at the Oxide Interfaces

TL;DR

This paper predicts a novel two-dimensional spin-polarized electron gas at oxide interfaces using first-principles calculations, revealing potential for spintronic applications in complex oxides.

Contribution

It introduces the first theoretical prediction of a 2D spin-polarized electron gas at LaMnO₃/SrMnO₃ interfaces based on density-functional theory.

Findings

Confined d-electrons form a potential well at the interface.

Electrons mediate ferromagnetic alignment of Mn spins.

The electron gas is spin-polarized due to magnetic fields.

Abstract

The formation of a novel spin-polarized 2D electron gas at the LaMnO$_3$ monolayer embedded in SrMnO$_3$ is predicted from the first-principles density-functional calculations. The La (d) electrons become confined in the direction normal to the interface in the potential well of the La layer, serving as a positively-charged layer of electron donors. These electrons mediate a ferromagnetic alignment of the Mn t$_{2g}$ spins near the interface via the Anderson-Hasegawa double exchange and become, in turn, spin-polarized due to the internal magnetic fields of the Mn moments.