Francesco Mattiotti — Università Cattolica del Sacro Cuore #
Decoupling absorption from transmission in light-harvesting devices #
Natural photosynthetic systems interact with different environments, which are a source of disorder but can also induce cooperative coherent effects, such as superabsorption of light and supertransfer of excitation. Both cooperativity and disorder are essential to achieve efficient energy transport in natural complexes and in bio-inspired quantum devices. Application of cooperative effects to design a bio-inspired light-harvesting system is studied in a model consisting of a ring of
donors surrounding a central core absorber. The working principle of this device is based on three steps: i) super-absorption of light from high energy states, ii) thermal relaxation which drives the excitation to low energy states, iii) supertransfer of the excitation from low energy states to the central core absorber. While in many relevant natural complexes absorbing and transferring states are the same, such device is based on the decoupling of absorption and transfer. The proposed device is able to outperform natural complexes in the same range of parameters and its efficiency increases with the system size.