Scaling relations in charge and spin excitations for (La,Sr)MnO3

TL;DR

This paper investigates the charge and spin excitations in (La,Sr)MnO3, combining theoretical and experimental approaches to understand their scaling relations, magnetic properties, and magnetoresistance in relation to the double-exchange model.

Contribution

It provides a comprehensive analysis of the scaling relations in charge and spin excitations of (La,Sr)MnO3 using both experimental data and dynamical mean-field theory, highlighting the role of the double-exchange Hamiltonian.

Findings

Charge and spin dynamics exhibit behaviors characteristic of half metals.

The double-exchange Hamiltonian explains various properties in high Curie temperature manganites.

Magnetoresistance is discussed in relation to spin and charge excitations.

Abstract

Scaling relations in the charge and spin excitations of (La,Sr)MnO3 are studied from both theoretical and experimental points of view. In the ferromagnetic metal phase, we investigate optical conductivity and neutron inelastic scattering, and compare with a theoretical calculation based on the dynamical mean-field theory of the double-exchange hamiltonian. Spin and charge dynamics of (La,Sr)MnO3 exhibit typical behaviors of half metals. In these manganite compounds with high Curie temperature, various behaviors in spin and charge properties are explained by the double-exchange hamiltonian alone. Magnetoresistance of these compounds as well as other compounds with lower Curie temperature are also discussed.