Correlated magnetism of moir\'e exciton-polaritons on a triangular electron-spin lattice

TL;DR

This paper demonstrates correlated magnetic phenomena in moiré exciton-polaritons within a heterostructure, revealing how electron interactions and strong light-matter coupling lead to nonlinear magnetic effects at specific electron fillings.

Contribution

It introduces the observation of correlated magnetism in moiré exciton-polaritons controlled by electron doping and cavity resonance, highlighting a new platform for studying many-body quantum phenomena.

Findings

Enhanced polariton Landé factor at one electron per moiré cell

Cavity-controlled resonance tuning of magnetic properties

Observation of nonlinear magnetic responses in moiré heterostructures

Abstract

We demonstrate evidence of correlated magnetism for exciton-polaritons in a MoSe$_{2}$/WS$_{2}$ moir\'e heterostructure with near-parallel alignment subject to electron doping. In our experiments, interactions between electrons and moir\'e excitons are controlled electrostatically by field-effect doping, and the polaritonic regime of strong light-matter coupling is established in an open cryogenic microcavity. Remarkably, at filling fractions around one electron per moir\'e cell, we observe drastic and nonlinear enhancement of the effective polariton Land\'e factor as a hallmark of correlated magnetism, which is cavity-controlled via resonance tuning of light and matter polariton constituents. Our work establishes moir\'e van der Waals heterostructures as an outstanding platform for studies of correlated phenomena in the presence of strong light-matter coupling and many-body phases of lattice-ordered excitons, charges and spins.