Dynamical electron correlations in metals: TB-LMTO and multiband Hubbard Hamiltonian

TL;DR

This paper investigates the electronic properties of correlated d-electron metals using a combined tight-binding LMTO approach and a multiband Hubbard model within a weak-interaction regime, revealing subtle correlation effects.

Contribution

It introduces a method combining TB-LMTO with FLEX-type approximations to study electron correlations in metals, especially in the weak-interaction limit.

Findings

DOS narrows due to correlations but remains similar at the Fermi level.

Satellite band in bcc Ni observed at 6 eV below Fermi level, matching experiments.

Electron correlations have limited impact on Fermi energy properties.

Abstract

We study electronic properties of solids with correlated d electrons which could be described by a multiband Hubbard Hamiltonian in the weak-interaction case, $U/w<1$. The one-electron part of the many-body Hamiltonian is described by a tight-binding LMTO method. The many-body part is treated by non-selfconsistent FLEX-type approximations with adjusted chemical potential not to change the LMTO band filling. The calculated DOS gets narrower but is only little influenced by electron correlations at the Fermi energy. A precursor of a satellite band in the paramagnetic bcc Ni is found at about 6 eV below the Fermi level in agreement with experiment.