In situ controllable magnetic phases in doped twisted bilayer transition-metal dichalcogenides

TL;DR

This paper investigates how magnetic phases in hole-doped twisted bilayer transition-metal dichalcogenides can be controlled in situ by the dielectric environment, revealing tunable ferromagnetic and antiferromagnetic correlations driven by electronic interactions.

Contribution

It provides the first demonstration of in situ control of magnetic phases in doped twisted bilayer TMDs using unbiased Monte Carlo simulations and analytical theory.

Findings

Weak spin-orbit coupling leads to antiferromagnetic correlations.

Strong spin-orbit coupling results in ferromagnetic correlations.

Magnetic behavior can be tuned by the dielectric environment.

Abstract

We study the electronic structure of hole-doped transition metal dichalcogenides for small twist-angels, where the onsite repulsion is extremely strong. Using unbiased diagrammatic Monte Carlo simulations, we find evidence for magnetic correlations which are driven by delocalization and can be controlled in situ via the dielectric environment. For weak spin-orbit coupling, we find that the moderately doped system becomes anti-ferromagnetic, whilst the regime of strong spin-orbit coupling features ferromagnetic correlations. We show that this behavior is accurately predicted by an analytical theory based on moment expansion of the Hamiltonian, and analysis of corresponding particle trajectories.