Non-universality of artificial frustrated spin systems

TL;DR

This study compares out-of-plane and in-plane magnetized artificial kagome nanomagnet arrays, revealing that long-range dipolar interactions significantly influence their magnetic configurations and challenge the notion of universal behavior in such frustrated spin systems.

Contribution

It demonstrates that long-range dipolar interactions are crucial in out-of-plane kagome nanomagnet arrays, showing limits to universality compared to in-plane systems.

Findings

Long-range dipolar interactions are significant in out-of-plane arrays.

Differences in magnetic configurations challenge universality.

Similar pairwise correlations despite different interaction ranges.

Abstract

Magnetic frustration effects in artificial kagome arrays of nanomagnets with out-of-plane magnetization are investigated using Magnetic Force Microscopy and Monte Carlo simulations. Experimental and theoretical results are compared to those found for the artificial kagome spin ice, in which the nanomagnets have in-plane magnetization. In contrast with what has been recently reported, we demonstrate that long range (i.e. beyond nearest-neighbors) dipolar interactions between the nanomagnets cannot be neglected when describing the magnetic configurations observed after demagnetizing the arrays using a field protocol. As a consequence, there are clear limits to any universality in the behavior of these two artificial frustrated spin systems. We provide arguments to explain why these two systems show striking similarities at first sight in the development of pairwise spin correlations.