Cuprates, Manganites, and Cobaltites: Multielectron Approach to the Band Structure

TL;DR

This paper introduces the LDA+GTB multielectron approach for calculating the electronic band structure of strongly correlated materials like cuprates, manganites, and cobaltites, addressing limitations of traditional Fermi-liquid methods.

Contribution

It presents a generalized multielectron method based on Hubbard perturbation theory and LDA parameters, offering a new way to understand complex band structures in correlated oxides.

Findings

Applied to cuprates, manganites, and cobaltites, demonstrating the method's effectiveness.

Provides insights into the low-energy physics of strongly correlated materials.

Addresses challenges in traditional band structure calculations for Mott insulators.

Abstract

High-$T_c$ superconductors with CuO$_2$ layers, manganites La$_{1-x}$Sr$_x$MnO$_3$, and cobaltites LaCoO$_3$ present several mysteries in their physical properties. Most of them are believed to come from the strongly-correlated nature of these materials. From the theoretical viewpoint, there are many hidden rocks in making the consistent description of the band structure and low-energy physics starting from the Fermi-liquid approach. Here we discuss the alternative method -- multielectron approach to the electronic structure calculations for the Mott insulators -- called LDA+GTB (local density approximation + generalized tight-binding) method. Its origin is a straightforward generalization of the Hubbard perturbation theory in the atomic limit and the multiband $p-d$ Hamiltonian with the parameters calculated within LDA. We briefly discuss the method and focus on its applications to cuprates, manganites, and cobaltites.