Ferrochiral, antiferrochiral, and ferrichiral skyrmion crystals in an itinerant honeycomb magnet

TL;DR

This paper theoretically predicts various topological skyrmion crystal phases in an itinerant honeycomb magnet, highlighting the role of spin, charge, and sublattice interactions without spin-orbit coupling.

Contribution

It introduces a new theoretical framework for understanding skyrmion crystals in honeycomb magnets, classifying three distinct types based on their topological spin textures.

Findings

Identification of ferrochiral, antiferrochiral, and ferrichiral skyrmion crystals

Skyrmion crystals arise from spin-orbit-coupling-free honeycomb structures

Potential for diverse emergent phenomena in itinerant honeycomb magnets

Abstract

Topological spin textures, such as a skyrmion crystal, are a source of unusual physical phenomena owing to the interplay between magnetism and topology. Since physical phenomena depend on the topological property and the symmetry of underlying spin structures, the search for new topological spin textures and emergent phenomena is one of the challenges in condensed matter physics. In this letter, we theoretically explore new topological spin textures arising from the synergy between spin, charge, and sublattice degrees of freedom in an itinerant magnet. By performing simulated annealing for an effective spin model of the honeycomb Kondo lattice model, we find a plethora of skyrmion crystal instabilities at low temperatures, whose topological spin textures are classified into three types: ferrochiral, antiferrochiral, and ferrichiral skyrmion crystals. We show that the obtained skyrmion crystals are the consequence of the spin-orbit-coupling-free honeycomb structure. Our results reveal the potential for itinerant honeycomb magnets to host a wide variety of SkXs and emergent phenomena.