Low-Temperature Spin Dynamics of Doped Manganites: roles of Mn-t2g and eg and O-2p states

TL;DR

This study models low-temperature spin dynamics in doped manganites using a tight-binding approach informed by ab initio calculations, highlighting the significant roles of Mn eg, t2g, and oxygen p states.

Contribution

It introduces a tight-binding model calibrated with ab initio data to analyze spin dynamics, emphasizing the importance of oxygen p states often overlooked.

Findings

Good agreement with ab initio results on spin dynamics

Oxygen p states significantly influence spin behavior

Challenges conventional model Hamiltonian assumptions

Abstract

The low-temperature spin dynamics of doped manganites have been analyzed within a tight-binding model, the parameters of which are estimated by mapping the results of ab initio density functional calculations onto the model. This approach is found to provide a good description of the spin dynamics of the doped manganites, observed earlier within the ab initio calculations. Our analysis not only provides some insight into the roles of the eg and the t2g states but also indicates that the oxygen p states play an important role in the spin dynamics. This may cast doubt on the adaptability of the conventional model Hamiltonian approaches to the analysis of spin dynamics of doped manganites.