UltrafasT flOquet PolaritonIcs metAsurfaces

2026-07-22

Electromagnetic waves interacting with materials give rise to polaritons, hybrid excitations of light and matter. Among these, hyperbolic phonon polaritons (HPhPs) in polar crystals stand out for their low loss and anisotropic behavior. Concurrently, Floquet theory has gained prominence in nanophotonics, enabling the engineering of topological properties in periodically driven systems. The UTOPIA project aims to merge these domains, establishing ultrafast Floquet polaritonics as a cutting-edge field. It seeks to demonstrate this concept in natural van der Waals materials and synthetic metasurfaces. Polariton research has evolved from plasmon polaritons to encompass phonons, excitons, and Cooper pairs. Phonon polaritons, with their anisotropic response, have opened avenues for nanophotonics. Recent discoveries in two-dimensional van der Waals materials like hexagonal boron nitride have unveiled hyperbolic polaritons in natural crystals. UTOPIA bridges phonon polaritons and Floquet theory, aiming to pioneer tailored light-matter interactions. Floquet systems endow physical systems with synthetic dimensions via periodic potentials, enabling nonreciprocal systems, topological phases, and 4+ dimensional physics. While Floquet quasi-energy states have been demonstrated in graphene, the field of Floquet polaritonics remains underexplored, lacking a demonstration of temporally driven changes in phonon polariton dispersion.UTOPIA's objectives include: 1) Demonstrating Floquet-driven topological polaritonic transitions via grating coupling in natural materials, mapping near-field observables to the far-field and enabling dynamical phase transitions. 2) Designing metasurfaces supporting synthetic hyperbolic polaritons, expanding Floquet polaritonics to optical frequencies and various temporal modulations.3) Achieving infrared light amplification via polariton-assisted anisotropic parametric amplification, harnessing polaritonic excitations for efficient amplification.

Italy

2026-02-15