Electrodynamics of nonstationary lattices
Phys. Rev. A 112, 023503 – Published 4 August, 2025
DOI: https://doi.org/10.1103/p38d-2pbk
Abstract
A model of a nonstationary metamaterial is introduced and its electromagnetic properties are studied. The metamaterial is composed of two sublattices: a stationary one and an activated one. It is shown that an initial polariton excites not only the usual frequency-shifted polaritons but also a mode consisting of almost out-of-phase sublattice oscillations coupled to the electromagnetic field and possessing a small negative group velocity. The presented framework forms a basic description of the processes in time-varying media with spatial dispersion.
