Multiple skyrmion crystal phases by itinerant frustration in centrosymmetric tetragonal magnets

TL;DR

This paper demonstrates the stabilization of multiple skyrmion crystal phases in centrosymmetric tetragonal magnets through itinerant frustration, revealing complex magnetic textures and potential transport phenomena.

Contribution

It introduces a numerical study showing three distinct skyrmion crystal phases stabilized by itinerant frustration in a specific magnetic system.

Findings

Three types of skyrmion crystals with different skyrmion numbers are stabilized.

External magnetic fields can induce transformations among these skyrmion phases.

Itinerant frustration due to electron interactions drives the formation of multiple SkXs.

Abstract

A skyrmion crystal (SkX) expressed as a multiple number of spiral modulations manifests itself not only in its peculiar magnetic texture but also in nontrivial transport properties originating from an emergent magnetic field. We here report our numerical results for multiple SkXs in a centrosymmetric tetragonal crystal system. By performing simulated annealing for an effective spin model for itinerant magnets, we find that three types of the SkXs with the skyrmion numbers of one and two, which are characterized by different superpositions of helices, are stabilized in the ground state, and are transformed by an external magnetic field. The essence of the emergent multiple SkXs is lied in itinerant frustration where exchange interactions are competed in momentum space due to the nature of itinerant electrons.