Heisenberg-exchange-free nanoskyrmion mosaic

TL;DR

This paper proposes a novel magnetic system where Dzyaloshinskii-Moriya interactions alone induce nanoscale skyrmions without Heisenberg exchange, enabling new topological spin textures for potential magnetic memory applications.

Contribution

It introduces a new paradigm of Heisenberg-exchange-free magnetism where Dzyaloshinskii-Moriya interactions alone create stable nanoscale skyrmions and magnetic mosaics.

Findings

Nanoskyrmions can be stabilized in small atomic clusters.

Dzyaloshinskii-Moriya interactions induce frustration leading to skyrmion formation.

Potential realization in ultracold gases or specific compounds.

Abstract

Isotropic Heisenberg exchange naturally appears as the main interaction in magnetism, usually favouring long-range spin-ordered phases. The anisotropic Dzyaloshinskii-Moriya interaction arises from relativistic corrections and is a priori much weaker, even though it may sufficiently compete with the isotropic one to yield new spin textures. Here, we challenge this well-established paradigm, and propose to explore a Heisenberg-exchange-free magnetic world. There, the Dzyaloshinskii-Moriya interaction induces magnetic frustration in two dimensions, from which the competition with an external magnetic field results in a new mechanism producing skyrmions of nanoscale size. The isolated nanoskyrmion can already be stabilized in a few-atom cluster, and may then be used as LEGO block to build a large magnetic mosaic. The realization of such topological spin nanotextures in sp- and p-electron compounds or in ultracold atomic gases would open a new route toward robust and compact magnetic memories.