TIMELIGHT · TIME-Varying Nanophotonics for New Regimes of QED LIGHT-Matter Interactions

Controlling light and its interaction with matter at the nanoscale is one of the major aims of current Science with applications ranging from energy-efficient photonic-based communications, quantum information processing, or high precision sensors. Owing to the hybrid light-matter modes supported by nanophotonic structures, from THz and IR polaritons in 2D materials to optical plasmonic resonances, nanophotonics offers an ideal platform for an exquisite control of light-matter interactions even at room temperature. Light concentrated at the nanoscale is a natural playground for quantum electro-dynamical (QED) processes, whereby light-matter interactions reveal their quantum nature. However, conventional approaches to nanophotonics-based QED are limited by two fundamental principles: energy conservation and reciprocity. Overcoming these limitations would enable non-photon conserving devices and one-way channels, opening the door to a compact route to quantum photonic circuits. TIMELIGHT proposes the use of time-modulated media, whose optical parameters (e.g., permittivity) are dynamically modulated by an external actuation, to realise fundamentally new non-Hermitian and non-reciprocal QED effects. This theoretical project roots in recent experimental advances that have shown unprecedentedly large and fast modulations of nanophotonic structures. TIMELIGHT will deliver advances in the following areas: (1) tuning of spontaneous emission and collective interactions of quantum emitters, (2) new forms of free electron radiation, (3) novel mechanisms for enhancing spontaneous photon generation, and (4) synthetic-motion based fluctuation-induced forces. TIMELIGHT will open the door to time-varying nanophotonics as a new paradigm to tailoring light-matter interactions at room temperature with non-Hermitian and non-reciprocal effects. This will shed light in the understanding of fundamental QED processes and ultimately be of interest to quantum photonic technologies.