WG2 Nonlinearities and ultrafast processes in nanostructured media.
- When an emitter is strongly coupled to a nanoscale field it combines the physics of cavity QED (e.g. quantum coherence, few-photon nonlinearities) with ultrafast dynamics that may be coherently controlled with femtosecond lasers at the quantum level. These settings may be pursued to achieve ultrafast optical switching with energies down to a few aJ, or be used to create artificial light-harvesting complexes (in combination with possible artificial “reaction centres”, in analogous way to the wellknown universal scheme of photosynthetic reaction centres of Nature) that convert single photons into electrical charges with a very high efficiency and rate.
- Nanofabrication of parametric devices for correlated photons and squeezed light generation to take quantum light sources closer to applications, like quantum key distribution (QKD) and quantum sensing, as it will facilitate scalability and increase robustness.
- Many questions remain regarding the role of plasmonics in enhancing (quantum) nonlinear processes for exciting novel applications, including strong coupling with quantum emitters, quantum frequency conversion of single photons, and nonlinear multiphoton processes. Plasmon-enhanced nonlinear effects could advance the development of nanoscale coherent light sources for lasing, nanoscopy and nanoimaging.
- The development of sensory tools based on quantum nonlinearities, including optomechanical quantum transducers constitutes an important topic to be covered.