Three-electron bunches in occupation of a 5-site Coulomb cluster

TL;DR

This paper investigates electron bunching phenomena in a 5-site Coulomb cluster, revealing that three-electron bunching occurs due to rearrangements influenced by screened Coulomb interactions, extending previous findings on electron attraction and bunching.

Contribution

It demonstrates for the first time that three-electron bunching can occur in a 5-site Coulomb cluster with screened interactions, expanding understanding of electron correlation effects.

Findings

Three-electron bunching observed in a 5-site Coulomb cluster.

Rearrangement of site occupations causes electron bunching.

Screened Coulomb repulsion facilitates complex occupation changes.

Abstract

Attraction of like charges in a localized system implies that, upon increasing the Fermi energy, the occupation of the system changes as, n\rightarrow (n+2), while the occupation, (n+1), is skipped. In this way, the attraction translates into the bunching of electrons. For a localized system of N=4 sites, attraction of electrons manifests itself in skipping of n=2 occupation. The origin of the attraction is rearrangement of the occupations of the surrounding sites which plays the role of a polaronic effect. We consider an N=5-site cluster and demonstrate that, with screened Coulomb repulsion, three-electron bunching becomes possible, i.e. the change of occupation n=1\rightarrow n=4 with n=2 and n=3 occupations skipped.