Correlated Electrons and Mass Enhancement on the Beta-Mn Type Lattice

TL;DR

This study investigates the electronic structure and correlations in the Hubbard model on the Beta-Mn lattice, revealing significant electron correlation effects and a large mass enhancement near n=1.1, which may explain experimental anomalies.

Contribution

It introduces a detailed analysis of electron correlations and mass enhancement on the Beta-Mn lattice using the momentum dependent local ansatz wavefunction method, highlighting unique correlation effects.

Findings

Electrons on the Beta-Mn lattice are more correlated than on fcc and bcc lattices.

The correlation energy gain is largest on the Beta-Mn lattice.

Mass enhancement peaks around electron number n=1.1, potentially explaining specific heat anomalies.

Abstract

Electronic structure and electron correlations of the Hubbard model on the Beta-Mn lattice have been investigated on the basis of the momentum dependent local ansatz wavefunction method. It is found that the electrons on the Beta-Mn lattice are significantly correlated as compared with those on the face centered cubic (fcc) and the body centered cubic (bcc) lattices; the correlation energy gain of the Beta-Mn lattice structure is the largest among the Beta-Mn, the fcc, and the bcc structures, and the charge fluctuations show a significant suppression. In particular, it is found that the mass enhancement factor on the Beta-Mn lattice shows a large peak around the electron number per atom n=1.1 when n is varied at the typical Coulomb interaction energy strength of transition metals. It is pointed that the large mass enhancement may explain anomalous electronic specific heat coefficient in Beta-Mn.