Towards a universal phase diagram of planar chiral magnets

TL;DR

This paper explores the complex phase diagram of planar chiral magnets by analyzing how various interactions and external fields influence their ground states, revealing a comprehensive classification of possible magnetic phases.

Contribution

It provides a complete analytical and numerical classification of ground states in planar chiral magnets with arbitrary DMI and magnetic field directions.

Findings

Classification of ground states into ferromagnetic, spiral, and skyrmion lattice phases.

Complete phase diagram for a broad class of DMI interactions.

Analytical and numerical methods combined for ground state determination.

Abstract

In planar chiral magnets, the competition of the positive definite Heisenberg exchange and Zeeman energies with the indefinite Dzyaloshinskii-Moriya interaction (DMI) energy allows for the possibility of negative energy ground states, and leads to an intricate dependence of the ground states on the parameters of the theory. In this paper, we consider arbitrary spiralization tensors for the DMI interaction and arbitrary directions for the external magnetic field, and study the nature of the ground states in this parameter space, using a combination of analytical and numerical methods. Classifying ground states by their symmetry into ferromagnetic (invariant under under arbitrary translations in the plane), spiral (invariant under arbitrary translations in one direction) and skyrmion lattice ground states (invariant under a two dimensional lattice group), we give a complete description of the phase diagram of this class of theories.