Cavity-QED-controlled two-dimensional Moir\'e Excitons without twisting

TL;DR

The paper introduces a novel all-optical method to emulate Moiré physics in two-dimensional excitons using spatially periodic optical cavities, revealing quantum fluctuation effects and cavity-mediated interactions.

Contribution

It develops a non-perturbative quantum electrodynamical model for excitons in structured cavities, demonstrating optical confinement effects analogous to Moiré patterns without twisting.

Findings

Classical laser-driven cavities emulate Moiré physics.

Quantum fluctuations cause significant excitonic band renormalization.

Cavity-mediated exciton-exciton interactions are long-range and non-perturbative.

Abstract

We propose an all-optical Moir\'e-like exciton confinement by means of spatially periodic optical cavities. Such periodic photonic structures can control the material properties by coupling the matter excitations to the confined photons and their quantum fluctuations. We develop a low energy non-perturbative quantum electro-dynamical description of strongly coupled excitons and photons at finite momentum transfer. We find that in the classical limit of a laser driven cavity the induced optical confinement directly emulates Moir\'e physics. In a dark cavity instead, the sole presence of quantum fluctuations of light generates a sizable renormalization of the excitonic bands and effective mass. We attribute these effects to long-range cavity-mediated exciton-exciton interactions which can only be captured in a non-perturbative treatment. With these findings we propose spatially structured cavities as a promising avenue for cavity material engineering.