Field-Direction Sensitive Skyrmion Crystals in Cubic Chiral Systems: Implication to $4f$-Electron Compound EuPtSi

TL;DR

This paper theoretically investigates the stability and formation mechanisms of nanometric skyrmion crystals in EuPtSi, highlighting the roles of low-symmetry ordering vectors and spin-charge coupling in chiral cubic antiferromagnets.

Contribution

It reveals the microscopic mechanisms behind skyrmion crystal stability in EuPtSi, emphasizing the importance of field-direction sensitivity and itinerant electron effects.

Findings

Identification of low-symmetric ordering vectors as key to field-sensitive SkXs

Demonstration of synergy between spin-charge and spin-orbit couplings for nanometric SkXs

Guidance for discovering new materials with short-period SkXs

Abstract

We theoretically study the stability of magnetic skyrmion crystals (SkXs) in chiral cubic antiferromagnets with the EuPtSi hosting unconventional nanometric SkXs in mind. By performing numerical simulations for a minimal effective spin model with the long-range Dzyaloshinskii-Moriya interaction and the multiple-spin interaction arising from itinerant nature of electrons, we clarify two key ingredients for the emergence of the SkXs in EuPtSi: One is the low-symmetric ordering vectors that lead to the field-direction sensitive SkXs in an external magnetic field, while the other is the synergy between spin-charge and spin-orbit couplings in itinerant magnets that results in the nanometric SkXs. The present study will not only provide the microscopic mechanism of the SkXs in EuPtSi but also guide for a search of further materials hosting short-period SkXs.