Navigation Links
Berkeley Lab scientists control light scattering in graphene
Date:3/16/2011

nondistinguishable pathways that interfere with one another, blocking one path can either decrease or increase the light from scattering, depending on whether that pathway was interfering constructively or destructively with the others. In graphene, the lower and higher-energy pathways interfered destructively. Removing one of them thus increased the brightness of the emission.

"What we've demonstrated is the quantum-interference nature of Raman scattering," Wang says. "It was always there, but it was so hard to see that it was often overlooked."

In a second observation, the researchers found yet another unexpected example of inelastic light scattering. This one, "hot electron luminescence," didn't result from blocked quantum pathways, however.

When a strong voltage is applied and the graphene's Fermi energy is lowered, higher-energy electron states are emptied from the filled band. Electrons that are highly excited by incoming photons, enough to jump to the unfilled band, thus find additional chances to fall back to the now-vacant states in what was the filled band. But these "hot" electrons can only fall back if they emit a photon of the right frequency. The hot electron luminescence observed by the researchers has an integrated intensity a hundred times stronger than the Raman scattering.

The road taken

The poet Robert Frost wrote of coming upon two roads that diverged in a wood, and was sorry he could not travel both. Not only can quantum processes take both roads at once, they can interfere with themselves in doing so.

The research team, working at UC Berkeley and at Berkeley Lab's Advanced Light Source, has shown that inelastic light scattering can be controlled by controlling interference between the intermediate states between photon absorption and emission. Manipulating that interference has enabled new kinds of quantum control of chemical reactions, as well as of "spintronic" states,
'/>"/>

Contact: Paul Preuss
paul_preuss@lbl.gov
510-486-6249
DOE/Lawrence Berkeley National Laboratory
Source:Eurekalert  

Page: 1 2 3 4 5

Related biology technology :

1. Strange new twist: Berkeley researchers discover Möbius symmetry in metamaterials
2. Berkeley Law Survey Challenges Popular Beliefs About Hi-tech Startup Patents
3. Grove Gift Launches Translational Medicine Program at UCSF & UC Berkeley
4. Berkeley Lab scientists create molecular paper
5. LS9, Inc., U.C Berkeley, and JBEI Make Major Breakthrough in Cellulosic Fuels Production
6. Berkeley researchers take the lead out of piezoelectrics
7. Berkeley researchers find new route to nano self-assembly
8. DOE to Explore Scientific Cloud Computing at Argonne, Lawrence Berkeley National Laboratories
9. Now, the story can be told how scientists helped ID Amerithrax
10. Laboratory-grown urethras implanted in patients, scientists report
11. Cellular Dynamics International Scientists Report on Efficient Method to Produce Footprint-Free Induced Pluripotent Stem Cells (iPSCs) Under Feeder-Free Conditions
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Berkeley Lab scientists control light scattering in graphene
(Date:7/24/2014)... -- A novel combination of microscopy and data processing ... Ridge National Laboratory an unprecedented look at the surface ... electrochemical properties. , The research team led by ... of a perovskite manganite, a complex material that exhibits ... understand surface behavior could benefit researchers who are interested ...
(Date:7/24/2014)... , July 24, 2014  Asterias Biotherapeutics, Inc. ... emerging field of regenerative medicine, announced today that ... presentation to investors on Tuesday, July 29, 2014, ... presentation will include an overview of Asterias, business ... webcast, visit http://www.ustream.tv/channel/asterias-biotherapeutics at least 15 ...
(Date:7/24/2014)... by group leader Yung-Eun Sung has announced that ... and nitrogen-doped graphenes which can be applied as ... cells. Yung-Eun Sung is both a group leader ... for Basic Science* (IBS) and a professor at ... great significance with regards to the development of ...
(Date:7/24/2014)... most natural and synthetic processes prefer to settle ... or energyit is within the realm of non-equilibrium ... constant changes in energy and phases, such as ... conditions allow humans to regulate their body temperature, ... with seismic activity. , But even though ...
Breaking Biology Technology:ORNL study reveals new characteristics of complex oxide surfaces 2Asterias Biotherapeutics Announces Live Investor Webcast 2Asterias Biotherapeutics Announces Live Investor Webcast 3Asterias Biotherapeutics Announces Live Investor Webcast 4New approach to form non-equilibrium structures 2
... , , , , , ... in eukaryotic cell cultures , requires double-stranded molecules known ... licensed supplier of siRNA, offering a custom , ... directed against common target genes, and a Cancer , ...
... For transfection of eukaryotic cells with RNA and siRNA , , , , , , ... Kit Contents , Storage and Stability ... Technical Assistance , Product Use Limitations ... Safety Information , ...
... QIAshredder spin columns are designed for simple and rapid homogenization , of cell and tissue lysates. ... , , Format: , ... , , Sample source: , ... plant cell or tissue lysates, white blood cell lysates, , ...
Cached Biology Technology:RNAi Gene Silencing System 2RNAi Gene Silencing System 3TransMessenger Transfection Reagent Handbook 2TransMessenger Transfection Reagent Handbook 3TransMessenger Transfection Reagent Handbook 4TransMessenger Transfection Reagent Handbook 5TransMessenger Transfection Reagent Handbook 6TransMessenger Transfection Reagent Handbook 7TransMessenger Transfection Reagent Handbook 8TransMessenger Transfection Reagent Handbook 9TransMessenger Transfection Reagent Handbook 10TransMessenger Transfection Reagent Handbook 11TransMessenger Transfection Reagent Handbook 12TransMessenger Transfection Reagent Handbook 13TransMessenger Transfection Reagent Handbook 14TransMessenger Transfection Reagent Handbook 15TransMessenger Transfection Reagent Handbook 16TransMessenger Transfection Reagent Handbook 17TransMessenger Transfection Reagent Handbook 18TransMessenger Transfection Reagent Handbook 19TransMessenger Transfection Reagent Handbook 20TransMessenger Transfection Reagent Handbook 21TransMessenger Transfection Reagent Handbook 22TransMessenger Transfection Reagent Handbook 23TransMessenger Transfection Reagent Handbook 24TransMessenger Transfection Reagent Handbook 25QIAshredder Homogenizer 2
(Date:7/28/2014)... Roald Amundsen became the first man to reach the ... years later, an international team of scientists led by ... proven that air pollution from industrial activities arrived long ... from widely spaced locations around the Antarctic continent, including ... and precise reconstruction to date of lead pollution over ...
(Date:7/27/2014)... in vitro study has revealed that nicotine and cotinine, ... caused by a certain carcinogen in smoke. , The ... of tobacco leaves and ultimately ends up in the ... lung and liver, where it is activated by a ... in mice has revealed that nicotine can partially interfere ...
(Date:7/27/2014)... that wiped them out if it had taken place ... A fresh study using up-to-date fossil records and improved ... narrative of the prehistoric creatures, demise, some 66 million ... million years before a 10km-wide asteroid struck what is ... extensive volcanic activity, changing sea levels and varying temperatures. ...
Breaking Biology News(10 mins):Industrial lead pollution beat explorers to the South Pole by 22 years and persists today 2Industrial lead pollution beat explorers to the South Pole by 22 years and persists today 3Nicotine found to inhibit DNA-strand break caused by a certain carcinogen in smoke 2Dinosaurs fell victim to perfect storm of events, study shows 2
... to make proteins, key building blocks of all organisms, ... instructions for assembling them. An Iowa State ... marking where these instructions are located in a cell,s ... Journal of Biological Chemistry , Michael Shogren-Knaak, assistant professor ...
... Service scientists have completed a study on a beetle that ... attacked 67 percent of the oak trees in an area ... in the current issue of The Pan-Pacific Entomologist ... so rare it does not even have an accepted common ...
... of Eve to the venomous murder of the mighty Thor, ... of mischief and misery. The worldwide prominence of ... to the serpentbut why, when so few of us have ... Davis, anthropology professor Lynne A. Isbell suggests, lies in the ...
Cached Biology News:New Southern California beetle killing oaks 2
Viral CMV UL146/vCXC1 Biotinylated Affinity Purified PAb...
Cyan Standard is 7-hydroxy-4-trifluoromethylcoumarin...
... small volume applications, including pediatric, neonatal, geriatric, general adult, veterinary and experimental animals. Automatic Calibration with ... ... ... ...
X-Gal, 100 mg. 5-Bromo-4-chloro-3-indolyl-b-d-galactoside.Histochemical substrate for b-galactosidase, used in blue/white screening.Store at -20 C. Protect from moisture. Category: Nucleotides & Enzy...
Biology Products: