Featured Research

from universities, journals, and other organizations

Photonic interactions measured at atomic level

Date:
August 30, 2012
Source:
Duke University
Summary:
By measuring the unique properties of light on the scale of a single atom, researchers believe that they have characterized the limits of metal's ability in devices that enhance light.

This is an artistic representation of the film-nanoparticle plasmonic system. Spherical gold nanoparticles are coupled to a gold film substrate by means of an ultrathin layer that forbids the particles from directly touching the film. Electromagnetic ultra-hot spots are excited in the gaps. The system enables the science of light on a scale of a few tenths of a nanometer, the diameter of a typical atom.
Credit: Sebastian Nicosia and Cristian Cirac

By measuring the unique properties of light on the scale of a single atom, researchers from Duke University and Imperial College, London, believe that they have characterized the limits of the ability of metals to be used in devices that rely on the enhancement of light.

This field is known as plasmonics because scientists are trying to take advantage of plasmons, electrons that have been "excited" by light in a phenomenon that produces electromagnetic field enhancement. The enhancement achieved by means of metals at the nanoscale is significantly higher than that achievable with any other material.

Until now, researchers have been unable to quantify plasmonic interactions at very small sizes, and thus have been unable to quantify the practical limitations of light enhancement. This new knowledge should help in the development of devices, such as medical sensors and integrated photonic communications components, since scientists will have a roadmap for precisely controlling the scattering of light.

Typically, plasmonic devices involve the interactions of electrons between two metal particles separated by a very short distance. For the past 40 years, scientists have been trying to figure out what happens when these particles are brought closer and closer, at sub-nanometer distances, according to the Duke electrical engineers.

"We were able to demonstrate the accuracy of our model by studying the optical scattering from gold nanoparticles interacting with a gold film," said Cristian Ciracì, postdoctoral fellow at Duke's Pratt School of Engineering. "Our results provide a strong experimental support in setting an upper limit to the maximum field enhancement achievable with plasmonic systems."

The results of Ciracì and co-workers' experiments, which were conducted in the laboratory of senior researcher David R. Smith, William Bevan Professor of electrical and computer engineering at Duke, were published in the journal Science as the cover article.

In their experiments, Ciracì and his team started with a thin gold film coated with a ultra-thin monolayer of organic molecules, studded with precisely controllable carbon chains. Nanometric gold spheres were dispersed on top of the monolayer. Essential to the experiment was that the distance between the spheres and the film could be adjusted with a precision of a single atom. In this fashion, the researchers were able to overcome the limitations of traditional approaches and obtain a photonic signature with atom-level resolution.

"Once you know maximum field enhancement, you can then figure out the efficiencies of any plasmonic system," Smith said. "It also allows us to 'tune' the plasmonic system to get exact predictable enhancements, now that we know what is happening at the atomic level. Control over this phenomenon has deep ramifications for nonlinear and quantum optics."

The Duke team worked with colleagues at Imperial College, specifically Sir John Pendry, who has long collaborated with Smith.

"This paper takes experiment beyond nano and explores the science of light on a scale of a few tenths of a nanometer, the diameter of a typical atom," said Pendry, physicist and co-director of the Centre for Plasmonics and Metamaterials at Imperial College. "We hope to exploit this advance to enable photons, normally a few hundred nanometers in size, to interact intensely with atoms which are a thousand times smaller."

The research was supported by the Air Force Office of Scientific Research and by the Army Research Office's Multidisciplinary University Research Initiative (MURI).

The other members of the team were Duke's Ryan Hill, Jack Mock, Yaroslav Urzhumov and Ashutosh Chilkoti; and from Imperial College, Antonio Fernández-Domínguez and Stefan Maier.


Story Source:

The above story is based on materials provided by Duke University. The original article was written by Richard Merritt. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Ciraci, R. T. Hill, J. J. Mock, Y. Urzhumov, A. I. Fernandez-Dominguez, S. A. Maier, J. B. Pendry, A. Chilkoti, D. R. Smith. Probing the Ultimate Limits of Plasmonic Enhancement. Science, 2012; 337 (6098): 1072 DOI: 10.1126/science.1224823

Cite This Page:

Duke University. "Photonic interactions measured at atomic level." ScienceDaily. ScienceDaily, 30 August 2012. <www.sciencedaily.com/releases/2012/08/120830173344.htm>.
Duke University. (2012, August 30). Photonic interactions measured at atomic level. ScienceDaily. Retrieved August 23, 2014 from www.sciencedaily.com/releases/2012/08/120830173344.htm
Duke University. "Photonic interactions measured at atomic level." ScienceDaily. www.sciencedaily.com/releases/2012/08/120830173344.htm (accessed August 23, 2014).

Share This




More Matter & Energy News

Saturday, August 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is It a Plane? No, It's a Hoverbike

Is It a Plane? No, It's a Hoverbike

Reuters - Business Video Online (Aug. 22, 2014) — UK-based Malloy Aeronautics is preparing to test a manned quadcopter capable of out-manouvering a helicopter and presenting a new paradigm for aerial vehicles. A 1/3-sized scale model is already gaining popularity with drone enthusiasts around the world, with the full-sized manned model expected to take flight in the near future. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) — China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Former TSA X-Ray Scanners Easily Tricked To Miss Weapons

Newsy (Aug. 21, 2014) — Researchers found the scanners could be duped simply by placing a weapon off to the side of the body or encasing it under a plastic shield. Video provided by Newsy
Powered by NewsLook.com
Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) — Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins