Nanograin ferromagnets from non-magnetic bulk materials: the case of gold nanoclusters

TL;DR

This paper demonstrates the emergence of ferromagnetism in gold nanoclusters through a detailed theoretical model that incorporates electron interactions and spin-orbit effects, revealing conditions for magnetic order in non-magnetic bulk materials.

Contribution

It introduces a novel two-dimensional lattice model with hybridized bands and exact solutions for ferromagnetism in gold nanoclusters, advancing understanding of nanoscale magnetic phenomena.

Findings

Exact ferromagnetic ground state identified

Model incorporates spin-orbit interactions and hybridized bands

Provides theoretical basis for ferromagnetism in gold nanoclusters

Abstract

The ferromagnetism of Au nanograins is analysed based on a two-dimensional itinerant lattice model with on-site Coulomb repulsion, many-body spin-orbit interactions, and holding two hybridized bands, one correlated and one uncorrelated. Using periodic boundary conditions in both directions, an exact ferromagnetic ground state is deduced for this non-integrable system by applying special techniques based on positive semidefinite operators.