Orbital correlations in monolayer manganites - From spin t-J model to orbital t-J model

TL;DR

This paper applies and extends the orbital t-J model to monolayer manganites, analyzing spin and orbital correlations with exact diagonalization and Monte Carlo methods, reproducing several experimental observations.

Contribution

It introduces a realistic orbital t-J model for e_g electrons in monolayer manganites and demonstrates its effectiveness in capturing experimental phenomena.

Findings

Reproduces experimental results on spin and orbital correlations.

Shows evolution of correlations with doping levels.

Validates the orbital t-J model as a useful tool for strongly correlated oxides.

Abstract

On the example of monolayer manganites we show that the theoretical ideas developed long ago along the derivation of the spin t-J model from the Hubbard model are nowadays very helpful in strongly correlated oxides with partly filled degenerate orbitals. We analyze a realistic orbital t-J model for e_g electrons in La_{1-x}Sr_{1+x}MnO_4 monolayer manganites, and discuss the evolution of spin and orbital correlations under increasing doping by performing exact diagonalization of finite clusters, with electronic kinetic energy determined self-consistently at finite temperature by classical Monte Carlo for t_2g spins. Several experimental results are reproduced.