Quantum Skyrmion Lattices in Heisenberg Ferromagnets

TL;DR

This paper predicts and characterizes quantum skyrmion lattices in two-dimensional quantum spin systems, highlighting their unique quantum properties and potential experimental detection methods.

Contribution

It introduces the existence of quantum skyrmion lattices in Heisenberg models with Dzyaloshinskii-Moriya interactions and analyzes their quantum entanglement features.

Findings

Quantum skyrmion lattices exist in certain phase regions.

They can be detected via magnetization and neutron scattering.

Quantum skyrmions exhibit entanglement near their boundaries.

Abstract

Skyrmions are topological magnetic textures that can arise in non-centrosymmetric ferromagnetic materials. In most systems experimentally investigated to date, skyrmions emerge as classical objects. However, the discovery of skyrmions with nanometer length scales has sparked interest in their quantum properties. Here, we simulate the ground states of two-dimensional spin-$1/2$ Heisenberg lattices with Dzyaloshinskii-Moriya interactions and discover a broad region in the zero-temperature phase diagram which hosts quantum skyrmion lattices. We argue that the quantum skyrmion lattice phase can be detected experimentally in the magnetization profile via local magnetic polarization measurements as well as in the spin structure factor measurable via neutron scattering experiments. Finally, we explore the resulting quantum skyrmion state, analyze its real-space polarization profile and show that it is a non-classical state featuring entanglement between quasiparticle and environment mainly localized near the boundary spins of the skyrmion.