Electronic and Magnetic Reconstructions in Manganite Superlattices

TL;DR

This study explores how electronic and magnetic properties at interfaces in manganite superlattices depend on layer thickness, revealing how magnetic moments, charge transfer, and transport behaviors are influenced by layer dimensions and interface effects.

Contribution

It introduces a detailed model of electronic and magnetic reconstructions in FM/AFI manganite superlattices considering multiple interactions and layer thickness effects.

Findings

Ferromagnetic moments in AFI layers decrease with increasing layer width.

Charge transfer and magnetic profiles approach bulk behavior with thicker AFI layers.

Magnetoresistance and metal-insulator transitions are controlled by layer width and charge transfer.

Abstract

We investigate the electronic reconstruction at the interface between ferromagnetic metallic (FM) and antiferromagnetic insulating (AFI) manganites in superlattices using a two-orbital double-exchange model including superexchange interactions, Jahn-Teller lattice distortions, and long range Coulomb interactions. The magnetic and the transport properties critically depend on the thickness of the AFI layers. We focus on superlattices where the constituent parent manganites have the same electron density n = 0.6. The induced ferromagnetic moment in the AFI layers decreases monotonically with increasing layer width, and the electron-density profile and the magnetic structure in the center of the AFI layer gradually return to the bulk limit. The width of the AFI layers and the charge-transfer profile at the interfaces control the magnitude of the magnetoresistance and the metal-insulator transition of the FM/AFI superlattices.