Phase shift, ellipticity, angle, and topological number in skyrmion lattices

TL;DR

This paper theoretically investigates the properties of skyrmion lattices in a Kondo lattice model, focusing on phase, ellipticity, and angle parameters, and how they change during topological transitions driven by magnetic fields.

Contribution

It analyzes numerical data to extract key parameters of skyrmion lattices with different topological numbers, revealing their modulation during topological transitions.

Findings

Topological transition involves significant modulation of phase, ellipticity, and angle.

Parameters differ between skyrmion number 1 and 2 lattices.

External magnetic field drives the transition between different skyrmion topologies.

Abstract

We theoretically study skyrmion lattices realized in a Kondo lattice model on a triangular lattice, focusing on the phase, ellipticity, and angle of the constituent multiple-$Q$ waves. Analyzing the numerical data obtained in the previous study [Ozawa R, Hayami S and Motome Y 2017 Phys. Rev. Lett. 118 147205], we extract these parameters for the two types of skyrmion lattices with the skyrmion number of $1$ and $2$. We show that the topological transition between the two skyrmion lattices driven by an external magnetic field is accompanied by significant modulations of all three parameters.