Tilted Material in an Optical Cavity: Light-Matter Moir\'e Effect and Coherent Frequency Conversion

TL;DR

This paper introduces a novel light-matter moiré effect caused by tilting a 2D material inside an optical cavity, leading to new polariton band structures and enabling coherent frequency conversion for quantum device applications.

Contribution

It theoretically characterizes the light-matter moiré effect induced by tilt in optical cavities, a new approach distinct from stacking layered 2D materials at twist angles.

Findings

Tilt induces emergent periodicity in light-matter coupling.

Flat polariton bands emerge near the Brillouin-zone center.

LMME enables robust coherent frequency conversion.

Abstract

Exciton-polaritons formed inside optical cavities offer a highly tunable platform for exploring novel quantum phenomena. Here, we introduce and theoretically characterize a light-matter moir\'e effect (LMME) that arises when a 2D material is tilted inside a planar optical cavity, in contrast to stacking multiple layers at a twist angle as is done in forming 2D moir\'e hetero-structures. We show that this geometric tilt produces emergent periodicity in the light-matter coupling, yielding displaced replicas of the polariton dispersion and flat bands near the Brillouin-zone center. Through time-dependent quantum dynamical simulations, we demonstrate that LMME enables coherent frequency conversion and remains robust against phonon-induced decoherence. Our findings establish LMME as a new platform for engineering polariton band structures, the generation of flat bands and performing coherent frequency conversion relevant for developing polariton-based quantum devices.