Ab-initio spin dynamics applied to nanoparticles: canted magnetism of a finite Co chain along a Pt(111) surface step edge

TL;DR

This paper extends relativistic spin dynamics methods to surface nanostructures, successfully predicting the canted magnetic ground state of a finite Co chain on Pt(111) with experimental agreement.

Contribution

It introduces a relativistic adiabatic spin dynamics approach for surface nanostructures and applies it to reveal canted magnetism in a Co chain on Pt(111).

Findings

Excellent agreement with experimental spin orientation.

Observation of noncollinear spin and orbital moments.

Symmetry reduction leads to canted magnetic states.

Abstract

In order to search for the magnetic ground state of surface nanostructures we extended first principles adiabatic spin dynamics to the case of fully relativistic electron scattering. Our method relies on a constrained density functional theory whereby the evolution of the orientations of the spin-moments results from a semi-classical Landau-Lifshitz equation. This approach is applied to a study of the ground state of a finite Co chain placed along a step edge of a Pt(111) surface. As far as the ground state spin orientation is concerned we obtain excellent agreement with the experiment. Furthermore we observe noncollinearity of the atom-resolved spin and orbital moments. In terms of magnetic force theorem calculations we also demonstrate how a reduction of symmetry leads to the existence of canted magnetic states.