Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Ultrafast technique unlocks design principles of quantum biology

University of Chicago researchers have created a synthetic compound that mimics the complex quantum dynamics observed in photosynthesis. The compound may enable fundamentally new routes to creative solar light harvesting technologies.

Credit: Graham Griffin
University of Chicago researchers have created a synthetic compound that mimics the complex quantum dynamics observed in photosynthesis. The compound may enable fundamentally new routes to creative solar light harvesting technologies.

Credit: Graham Griffin

Abstract:
University of Chicago researchers have created a synthetic compound that mimics the complex quantum dynamics observed in photosynthesis and may enable fundamentally new routes to creating solar-energy technologies. Engineering quantum effects into synthetic light-harvesting devices is not only possible, but also easier than anyone expected, the researchers report in the April 18 edition of Science Express.

Ultrafast technique unlocks design principles of quantum biology

Chicago, IL | Posted on April 21st, 2013

The researchers have engineered small molecules that support long-lived quantum coherences. Coherences are the macroscopically observable behavior of quantum superpositions. Superpositions are a fundamental quantum mechanical concept, exemplified by the classic Schrodinger's Cat thought experiment, in which a single quantum particle such as an electron occupies more than one state simultaneously.

Quantum effects are generally negligible in large, hot, disordered systems. Nevertheless, the recent ultrafast spectroscopy experiments in UChicago chemistry Prof. Greg Engel's laboratory have shown that quantum superpositions may play a role in the near perfect quantum efficiency of photosynthetic light harvesting, even at physiological temperatures.

Photosynthetic antennae - the proteins that organize chlorophylls and other light-absorbing molecules in plants and bacteria - support superpositions that survive for anomalously long times. Many researchers have proposed that organisms have evolved a means of protecting these superpositions. The result: improved efficiency in transferring energy from absorbed sunlight to the parts of the cell that convert solar energy to chemical energy. The newly reported results demonstrate that his particular manifestation of quantum mechanics can be engineered into man-made compounds.

The researchers modified fluorescein - the same molecule once used to dye the Chicago River green for St. Patrick's Day - and then linked different pairs of these dyes together using a rigid bridging structure. The resulting molecules were able to recreate the important properties of chlorophyll molecules in photosynthetic systems that cause coherences to persist for tens of femtoseconds at room temperature.

"That may not sound like a very long time - a femtosecond is a millionth of a billionth of a second," said study co-author Dugan Hayes, a UChicago graduate student in chemistry. "But the movement of excitations through these systems also occurs on this ultrafast timescale, meaning that these quantum superpositions can play an important role in energy transfer."

To detect evidence of long-lived superpositions, the researchers created a movie of energy flow in the molecules using highly engineered laboratories and state-of-the-art femtosecond laser systems. Three precisely controlled laser pulses are directed into the sample, causing it to emit an optical signal that is captured and directed into a camera.

By scanning the time delays between the arriving laser pulses, the researchers create a movie of energy flow in the system, encoded as a series two-dimensional spectra. Each two-dimensional spectrum is a single frame of the movie, and contains information about where energy resides in the system and what pathways it has followed to get there.

These movies show relaxation from high energy states toward lower energy states as time proceeds, as well as oscillating signals in very specific regions of the signal, or quantum beats. "Quantum beats are the signature of quantum coherence, arising from the interference between the different energetic states in the superposition, similar to the beating heard when two instruments that are slightly out of tune with each other try to play the same note," Hayes explained.

Computer simulations have shown that quantum coherences work in photosynthetic antennae to prevent excitations from getting trapped on their way to the reaction center, where the conversion to chemical energy begins. In one interpretation, as the excitation moves through the antenna, it remains in a superposition of all possible paths at once, making it inevitable that it proceeds down the proper path. "Until these coherences were observed in synthetic systems, it remained dubious that such a complex phenomenon could be recreated outside of nature," Hayes said.

####

For more information, please click here

Contacts:
Steve Koppes

773-702-8366

Copyright © University of Chicago

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Meteorite impact on a nano scale August 29th, 2016

Designing ultrasound tools with Lego-like proteins August 29th, 2016

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Discoveries

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Meteorite impact on a nano scale August 29th, 2016

Designing ultrasound tools with Lego-like proteins August 29th, 2016

A promising route to the scalable production of highly crystalline graphene films August 26th, 2016

Announcements

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Meteorite impact on a nano scale August 29th, 2016

Designing ultrasound tools with Lego-like proteins August 29th, 2016

A nanoscale wireless communication system via plasmonic antennas: Greater control affords 'in-plane' transmission of waves at or near visible light August 27th, 2016

Energy

New electrical energy storage material shows its power: Nanomaterial combines attributes of both batteries and supercapacitors August 25th, 2016

Lehigh engineer discovers a high-speed nano-avalanche: New findings published in the Journal of Electrochemical Society about the process involving transformations in glass that occur under intense electrical and thermal conditions could lead the way to more energy-efficient glas August 24th, 2016

New flexible material can make any window 'smart' August 23rd, 2016

Researchers reduce expensive noble metals for fuel cell reactions August 22nd, 2016

Nanobiotechnology

Designing ultrasound tools with Lego-like proteins August 29th, 2016

Analog DNA circuit does math in a test tube: DNA computers could one day be programmed to diagnose and treat disease August 25th, 2016

Nanofiber scaffolds demonstrate new features in the behavior of stem and cancer cells August 25th, 2016

Johns Hopkins scientists track metabolic pathways to find drug combination for pancreatic cancer August 25th, 2016

Solar/Photovoltaic

Let's roll: Material for polymer solar cells may lend itself to large-area processing: 'Sweet spot' for mass-producing polymer solar cells may be far larger than dictated by the conventional wisdom August 12th, 2016

NREL technique leads to improved perovskite solar cells August 11th, 2016

Making a solar energy conversion breakthrough with help from a ferroelectrics pioneer: Philadelphia-based team shows how a ferroelectric insulator can surpass shockley-queisser limit August 9th, 2016

Tiny high-performance solar cells turn power generation sideways August 5th, 2016

Quantum nanoscience

Light and matter merge in quantum coupling: Rice University physicists probe photon-electron interactions in vacuum cavity experiments August 24th, 2016

Prototype chip could help make quantum computing practical: Built-in optics could enable chips that use trapped ions as quantum bits August 9th, 2016

Diamond-based light sources will lay a foundation for quantum communications of the future: Electrified quantum diamond can become the heart of quantum networks and computers of the future August 7th, 2016

Scientists discover light could exist in a previously unknown form August 6th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic