Effect of electron correlations in Pd, Ni, and Co monowires

TL;DR

This study examines how static electron correlations influence the electronic and magnetic properties of monatomic nanowires of Co, Ni, and Pd using density-functional methods, revealing selective effects on magnetic moments and conductance channels.

Contribution

It introduces a comparative analysis of LDA+SIC and LDA+U approaches to understand electron correlation effects in transition metal nanowires.

Findings

Electron correlations increase Pd monowire magnetic moments.

Magnetic moments in Co and Ni are unaffected by added correlations.

Number of $d$-dominated conductance channels decreases slightly.

Abstract

We investigated the effect of mean-field electron correlations on the band electronic structure of Co, Ni, and Pd ultra-thin monatomic nanowires, at the breaking point, by means of density-functional calculations in the self-interaction corrected LDA approach (LDA+SIC) and alternatively by the LDA+$U$ scheme. We find that adding static electron correlations increases the magnetic moment in Pd monowires, but has negligible effect on the magnetic moment in Co and Ni. Furthermore, the number of $d$-dominated conductance channels decreases somewhat compared to the LDA value, but the number of $s$-dominated channels is unaffected, and remains equal to one per spin.