Effect of strain on the orbital and magnetic ordering of manganite thin films and their interface with an insulator

TL;DR

This paper investigates how uniform uniaxial strain influences the electronic and magnetic properties of manganite thin films and their interfaces, revealing strain-induced orbital and magnetic order modifications.

Contribution

It introduces a model incorporating strain effects into manganite thin films, analyzing their impact on orbital and magnetic ordering at the microscopic level.

Findings

Strain causes orbital selection in manganite thin films.

Strain modifies magnetic ordering and electronic properties.

Interface properties are affected by lattice mismatch-induced strain.

Abstract

We study the effect of uniform uniaxial strain on the ground state electronic configuration of a thin film manganite. Our model Hamiltonian includes the double-exchange, the Jahn-Teller electron-lattice coupling, and the antiferromagnetic superexchange. The strain arises due to the lattice mismatch between an insulating substrate and a manganite which produces a tetragonal distortion. This is included in the model via a modification of the hopping amplitude and the introduction of an energy splitting between the Mn e_g levels. We analyze the bulk properties of half-doped manganites and the electronic reconstruction at the interface between a ferromagnetic and metallic manganite and the insulating substrate. The strain drives an orbital selection modifying the electronic properties and the magnetic ordering of manganites and their interfaces.