Magnetism in reduced dimensions

TL;DR

This paper provides an overview of key issues in magnetism at reduced dimensions, covering theoretical and experimental insights into anisotropy, magnetization states, interactions, and thermal effects.

Contribution

It offers a comprehensive summary of recent developments and foundational knowledge in the field of low-dimensional magnetism, bridging theory and experiment.

Findings

Discussion of magnetic anisotropy from surface to single-atom levels

Review of magnetization states including macrospins and domain walls

Analysis of dipolar interactions and superparamagnetism phenomena

Abstract

We propose a short overview of a few selected issues of magnetism in reduced dimensions, which are the most relevant to set the background for more specialized contributions to the present Special Issue. Magnetic anisotropy in reduced dimensions is discussed, on a theoretical basis, then with experimental reports and views from surface to single-atom anisotropy. Then conventional magnetization states are reviewed, including macrospins, single domains, multidomains, and domain walls in stripes. Dipolar coupling is examined for lateral interactions in arrays, and for interlayer interactions in films and dots. Finally thermally-assisted magnetization reversal and superparamagnetism are presented. For each topic we sought a balance between well established knowledge and recent developments.