Magnetic ground states of honeycomb lattice Wigner crystals

TL;DR

This study uses large-scale Hartree-Fock calculations to explore the magnetic phases of honeycomb lattice Wigner crystals in moiré materials, revealing complex spin arrangements and potential experimental signatures.

Contribution

It provides the first detailed magnetic phase diagrams for honeycomb lattice Wigner crystals at specific fillings, highlighting non-collinear and non-coplanar spin states.

Findings

Multiple magnetic phases at charge gaps n=2/3, 1/2, 1/3.

Presence of non-collinear and non-coplanar spin arrangements.

Magnetization behavior under external magnetic fields.

Abstract

Lattice Wigner crystal states stabilized by long-range Coulomb interactions have recently been realized in two-dimensional moir\'e materials. We employ large-scale unrestricted Hartree-Fock techniques to unveil the magnetic phase diagrams of honeycomb lattice Wigner crystals. For the three lattice filling factors with the largest charge gaps, n = 2/3, 1/2, 1/3, the magnetic phase diagrams contain multiple phases, including ones with non-collinear and non-coplanar spin arrangements. We discuss magnetization evolution with external magnetic field, which has potential as an experimental signature of exotic spin states. Our theoretical results could potentially be validated in moir\'e materials formed from group VI transition metal dichalcogenide twisted homobilayers.