Events

Excitonic Quantum Random Walk in Biological Phycocyanin Nanowires

October 6, 2015 at 4:30pm/ 36-428

Yossi Paltiel
Department of Applied Physics, The Hebrew University of Jerusalem

The importance of quantum processes in biology is starting to be recognized. Quantum processes are being discussed in the context of enzyme function, olfaction, magnetic sensing and most prominently in photosynthetic light-harvesting complexes. These findings suggest that a key to the survival of quantum coherence at ambient temperatures is the interplay between long-lived vibrational modes and the electronic degrees of freedom that can lead to coherent effects. This coherence can explain the high yield of photosynthetic exciton transfer. Furthermore, it is fair to say that no device made by man so far has made use of all these properties at the same time.

Our aim is to develop a new class of quantum coherent devices. This can be achieved by understanding the underlying mechanisms driving photosynthetic processes with efficient long range energy transfer and harness this knowledge to advance innovative quantum technologies. Utilizing light harvesting complexes we were able to fabricate self-assembled nano-energy guides. We used isolated Phycocyanin (PC) proteins that can self-assemble into bundles of nanowires. We show two methods for controlling the organization of the bundles. The optically excited nanowires exhibit long range quantum energy transfer through hundreds of proteins. Such results may provide new building blocks for coherent based nano-devices. In vivo desert adapted cyanobacteria seems to use the same organization for efficient energy removal. The suggested results open many questions regarding the distribution and the efficiency of energy transfer mechanisms in biological systems.

Professor Yossi Paltiel has worked in both leading high-tech industry groups and in the academic world.  Since July 2009, he’s been leading the Quantum Nano Engineering group at the Hebrew University, Israel and is currently chair of the Applied Physics department. Paltiel’s group’s goal is to establish a way to incorporate quantum mechanics into room temperature “classical” computation and reading schemes.  This will provide quantum coherence control at nanometer scale distances, while maintaining the physical characteristics of currently available computer input-output devices.  He has published more than 70 papers in leading journals and has issued 10 patents.  In 2013, he co-founded, Valentis Nanotech, a start-up company that combines nano particles with CNC (cellulose nano crystals) a biodegradable, transparent material made from plant pulp waste to produce a functional material, tailored to each industry according to its needs.