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

oating is designed so that the two pathways interfere with each other and cancel light that would otherwise cause reflection."

Wang adds, "The hallmark of quantum mechanics is that if different paths are nondistinguishable, they must always interfere with each other. We can manipulate the interference among the quantum pathways that are responsible for Raman scattering in graphene because of graphene's peculiar electronic structure."

In Raman scattering, the quantum pathways are electronic excitations, which are optically stimulated by the incoming photons. These excitations can only happen when the initial electronic state is filled (by a charged particle such as an electron), and the final electronic state is empty.

Quantum mechanics describes electrons filling a material's available electronic states much as water fills the space in a glass: the "water surface" is called the Fermi level. All the electronic states below it are filled and all the states above it are empty. The filled states can be reduced by "doping" the material in order to shift the Fermi energy lower. As the Fermi energy is lowered, the electronic states just above it are removed, and the excitation pathways originating from these states are also removed.

"We were able to control the excitation pathways in graphene by electrostatically doping it applying voltage to drive down the Fermi energy and eliminate selected states," Wang says. "An amazing thing about graphene is that its Fermi energy can be shifted by orders of magnitude larger than conventional materials. This is ultimately due to graphene's two-dimensionality and its unusual electronic bands."

The Fermi energy of undoped graphene is located at a single point, where its electronically filled bands, graphically represented as an upward-pointing cone, meet its electronically empty bands, represented as a downward-pointing cone. To move the Fermi energy appreciably requires a strong electri
'/>"/>

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:10/25/2014)... -- RegeneRx Biopharmaceuticals, Inc. (OTCBB: RGRX) ("the Company" or "RegeneRx") ... Symposium on Thymosins in Health and Disease in ... thymosin beta 4 (TB4) linked with rhodamine (a fluorescent ... a rodent model of stroke, it was visualized outside ... functional tissue of the brain).   The leakage of TB4 ...
(Date:10/22/2014)... -- Research and Markets has announced ... Market (Product types, Application, Technology, End User and ... Demand, Insights, Analysis, Research, Report, Opportunities, Segmentation and ... offering. This new report titled, ... and Geography) Global Size, Industry Analysis, Trends, Opportunities, ...
(Date:10/22/2014)... Involution Studios , a healthcare ... new infographic, Understanding Ebola . The goal ... easy to follow informative tool for anyone wanting to ... and prevention. , "As the news has spread in ... outbreak represents not only a healthcare crisis with global ...
(Date:10/22/2014)... (PRWEB) October 22, 2014 According ... Market by Service Type (Consulting, Integration, Deployment & ... by Deployment Model (Public, Private, Others (Hybrid & ... MarketsandMarkets, defines and segments the Cloud Professional Services ... and forecasting of revenues. It also identifies the ...
Breaking Biology Technology:Researchers Report Thymosin Beta 4 Crosses Blood-Brain Barrier In Animal Stroke Model 2Global DNA Diagnostics Market (Product types, Application, Technology, End User and Geography) - Forecast to 2020 2Global DNA Diagnostics Market (Product types, Application, Technology, End User and Geography) - Forecast to 2020 3Involution Studios' Ebola Infographic Provides Key Disease Information and Statistics at a Glance 2Cloud Professional Services Market by Public, Private, Hybrid & Community Expected to Reach $34.41 Billion by 2019 - New Report by MarketsandMarkets 2Cloud Professional Services Market by Public, Private, Hybrid & Community Expected to Reach $34.41 Billion by 2019 - New Report by MarketsandMarkets 3Cloud Professional Services Market by Public, Private, Hybrid & Community Expected to Reach $34.41 Billion by 2019 - New Report by MarketsandMarkets 4Cloud Professional Services Market by Public, Private, Hybrid & Community Expected to Reach $34.41 Billion by 2019 - New Report by MarketsandMarkets 5
... Medarex, Inc. (Nasdaq: MEDX ) announced today ... J.P. Morgan Healthcare Conference at 8:30 a.m. Pacific Time (11:30 ... will be webcast live and will be available in the ... . An archived edition of the presentation will be available ...
... PCYC ) today announced that in ... Associates ("RWD") made an unsecured loan to,Pharmacyclics, Inc. ... $5,000,000. As of,December 31, 2008, the company,s ... the $5,000,000 in loan proceeds. RWD,is controlled ...
... Jan. 6 Omeros Corporation today announced that The ... grant against milestones to support the Company,s collaboration with ... a new target for the treatment of Parkinson,s disease. ... disease, Omeros is the first to link its novel ...
Cached Biology Technology:Medarex to Present at the 27th Annual J.P. Morgan Healthcare Conference 2Pharmacyclics Secures $5.0 Million in Debt Financing 2Pharmacyclics Secures $5.0 Million in Debt Financing 3Omeros Awarded Grant from The Michael J. Fox Foundation to Evaluate Novel Parkinson's Disease Target 2Omeros Awarded Grant from The Michael J. Fox Foundation to Evaluate Novel Parkinson's Disease Target 3
(Date:10/17/2014)... . To date, ... overdoses, doctors are often limited to supportive therapy such as ... combination of drugs involved. So what can be done if ... ETH professor Jean-Christophe Leroux from the Institute of Pharmaceutical Sciences ... question. "The task was to develop an agent that could ...
(Date:10/16/2014)... Researchers at William and Mary,s Virginia Institute of ... from the Environmental Protection Agency to identify the ... and to develop tools to help local governments ... project depends critically on a dataset of tidal-marsh ... 1970s. Only with this historical baseline can today,s ...
(Date:10/16/2014)... have challenged conventional thinking on how the bowel lining ... for how bowel cancer starts. , The researchers produced ... regenerating the ,crypts, that are a feature of the ... in bowel cancer development, a controversial finding as scientists ... Using 3D imaging technologies, Dr Chin Wee Tan and ...
Breaking Biology News(10 mins):Emergency aid for overdoses 2Emergency aid for overdoses 3EPA grant will help localities conserve headwater wetlands 2EPA grant will help localities conserve headwater wetlands 3Cryptic clues drive new theory of bowel cancer development 2
... infectious diseases are urgently needed in resource-limited countries. ... Academy of Microbiology colloquium, "Bringing the Lab to ... Settings," describes the challenges inherent in bringing new ... the world where they are needed most. Point-of-care ...
... team of UC Davis investigators has found that a genetic ... prostate cancer. The mutation of the so-called p53 (or Tp53) ... now has never been shown to act as an initiating ... treating the disease. The study was published online ...
... one of the few probiotics with medical food designation for ... of more than 80 studies that have demonstrated its use ... ileal pouch. Ulcerative colitis patients, in particular, have been shown ... drug regimen. One particular study shows that the combination of ...
Cached Biology News:Report addresses challenges in implementing new diagnostic tests where they are needed most 2UC Davis scientists find new role for P53 genetic mutation -- initiation of prostate cancer 2By adding VSL#3 probiotic to traditional therapies UC patients can improve remission rates 2
Rabbit polyclonal to Quinolinic acid ( Abpromise for all tested applications). Antigen: Synthetic quinolinic acid conjugated to bovine serum albumin....
Human Cell Line Slides...
Tris-EDTA Buffer Solution, 1X, pH 8.0, sterile...
Mouse Cell Line Slides...
Biology Products: