Two-dimensional moir\'{e} phonon polaritons

TL;DR

This paper introduces a new class of moiré phonon polaritons in twisted 2D materials, showing their spectral and spatial properties can be engineered by superlattice structures, opening new avenues for light-matter interaction control.

Contribution

The study reveals the existence of moiré phonon polaritons with unique spectral and spatial features, confirmed through numerical simulations, advancing the understanding of hybrid modes in twisted 2D materials.

Findings

Moiré potential creates multiple spectral branches of PhPs.

Electromagnetic wavefunctions are nano-patterned by superlattice.

Nanoscale structuring leads to spatially varying near-field responses.

Abstract

Phonon polaritons (PhPs) are hybrid light-matter modes. We investigate them in two-dimensional (2D) materials with twisted moir\'{e} structures, revealing that the moir\'{e} potential creates a new class of `moir\'{e} PhPs'. These exhibit a fundamental spectral reconstruction into multiple branches and, crucially, electromagnetic wavefunctions that are nano-patterned by the superlattice. Through numerical simulations based on realistic lattice models, we confirm the existence of these intriguing modes. The inherent nanoscale structuring produces a robust, spatially varying near-field response, establishing moir\'{e} superlattices as a platform for engineering light-matter interactions.