Noise and entanglement: from natural photosynthesis to quantum communication

Description
Recently, we investigated the intricate interplay of noise and quantum coherence to explain the remarkable efficiency well above 90% for excitation energy transfer (EET) in light harvesting complexes during photosynthesis. Here, we analyze this scenario by exploiting theoretical tools of quantum information science. First of all, we study the role of entanglement in these biological networks, even in the case of spatially and temporally correlated noise and for different injection mechanisms, like thermal and coherent laser excitation. While quantum information processing tends to favour maximal entanglement, the optimal EET efficiency is achieved when the initial part of the evolution displays intermediate values of entanglement. Secondly, we investigate this transport dynamics in the elegant and powerful framework of quantum communication. Indeed, we solve analytically and numerically the highly non-trivial task of the calculation of the classical and quantum capacity of a communication channel associated to these photosynthetic systems. In particular, we find that the dephasing may enhance, in a very remarkable way, the capability of transmitting not only classical but also, more counterintuitively, quantum information over biologically inspired quantum communication networks.
Organised by Andrea Rapisarda