An experimental optical simulator to optimise energy transmission with an efficiency of almost 100%.
A low cost controllable optical-fiber platform to deeper understand natural photosynthesis process and to engineer new solar energy quantum technologies.
This is the result achieved by a group of researchers of the University of Florence - Filippo Caruso and Stefano Gherardini at the Department of Physics and Astronomy and at European Laboratory for Non-linear Spectroscopy (LENS), and Silvia Viciani, Manuela Lima and Marco Bellini at the National Istitute of Optics (INO) and the National Council for Research (CRN). This work has just been published in Nature - Scientific Reports ("Disorder and dephasing as control knobs for light transport in optical fiber cavity networks", www.nature.com/articles/srep37791 , doi:10.1038/srep37791).
The results obtained by the Florentine researchers stem from previous research in the field of quantum biology where phenomena such as photosynthesis, olfaction and bird navigation seem to rely on the interplay of the quantum effects characterizing the microscopic world (e.g. interference phenomena) and decoherence noise, which induces the transition from the quantum world to the classical one, which typically occurs because of the interaction between the quantum systems and the external environment.
“Even if it may seem counter-intuitive - as said by Filippo Caruso, principal investigator of this project - the unavoidable presence of noise can have a beneficial effect on the transport mechanism. Indeed, it is thanks to the so-called decoherence noise that slow and ineffective paths are suppressed while new shortcuts to reach the final destination are activated. These optical simulator would allow also to find the optimal molecular geometries for low-cost energy transport." In this experiment both static and dynamic noise was externally controlled via electronic devices, hence being able to analyse various transport regimes and find the maximum transmission efficiency.
Noise-assisted transport, known as NAT in literature, has been recently observed experimentally for the first time here in Florence and by the same research team. "Using such optical simulators, and inspired from nature, in particular from the way how natural photosynthetic organisms work - conclude Silvia Viciani and Marco Bellini - we will be able to develop more efficient and sustainable new technologies."
This research project was financially supported by Fondazione Cassa di Risparmio di Firenze, the Ministry of Education, University and Research via Future in Research (FIRB) funds, and the European Commission (Marie-Curie Fellowship projects).
In this figure a laser pulse is injected in a network of telecom optical fibers and then it reaches an external detector, thus mimicking the transport of solar energy, absorbed by an antenna and transmitted by a series of chromofores towards a reaction center where it is converted into chemical energy. The simulator has two external controls to manipulate static (disorder) and dynamic (dephasing) noise by which the transport efficiency disorder (static) can be tuned and optimised in order to study the quantum mechanisms underlying photosynthesis and to simulate new molecular geometries towards more efficient solar energy devices.