Comment on "Magnetism of Nanowires Driven by Novel Even-Odd Effects"

TL;DR

This paper comments on previous findings about the magnetic ground states of finite antiferromagnetic nanowires, proposing a simpler analytical approach to determine the transition length and clarifying the original results.

Contribution

It introduces a two-dimensional map method to analyze the Heisenberg model, providing an analytical expression for the transition length in nanowire magnetism.

Findings

Analytical expression for transition length derived

Simplified method for Heisenberg model analysis

Clarification of parity-dependent ground states

Abstract

In a recent Letter, S. Lounis et al. find that the ground state of finite antiferromagnetic nanowires deposited on ferromagnets depends on the parity of the number N of atoms and that a collinear-noncollinear transition exists for odd N. Authors use ab initio results and a Heisenberg model, which is studied numerically with an iterative scheme. In this Comment we argue that the Heisenberg model can much easier be investigated in terms of a two-dimensional map, which allows to find an analytic expression for the transition length, a central result of Lounis et al. (see their Fig.3).