Single quantum dot nanowire photodetectors

Newly fabricated devices are a step toward quantum computing

2010-12-15

(Press-News.org) Washington, D.C. (December 14, 2010) -- Moving a step closer toward quantum computing, a research team in the Netherlands recently fabricated a photodetector based on a single nanowire, in which the active element is a single quantum dot with a volume of a mere 7,000 cubic nanometers. The device is described in the American Institute of Physics' journal Applied Physics Letters.

Photodetectors based on single quantum dots are expected to find uses in optoelectrical interfaces in future quantum computers, where single photons will carry information over long distances and single electrons will be used for computation.

"Our research team fabricated a very localized light detector with dimensions far below the wavelength of light, which enables detection with very high spatial resolution," explains Val Zwiller of the Kavli Institute of Nanoscience at Delft University of Technology.

"In addition, because quantum dots have discrete energy levels, only light in resonance with the energy levels of the quantum dot will be detected. The indium phosphide (InP) nanowire was grown with standard epitaxial techniques and the quantum dot was obtained by sandwiching a thin segment in between with a lower bandgap. We created the device using electron beam lithography to contact a single nanowire."

INFORMATION:

The article, "Single quantum dot nanowire photodetectors" by M. P. van Kouwen, M. H. M. van Weert, M. E. Reimer, N. Akopian, U. Perinetti, R. E. Algra, E. P. A. M. Bakkers, L. P. Kouwenhoven, and V. Zwiller appears in the journal Applied Physics Letters. See: http://link.aip.org/link/applab/v97/i11/p113108/s1

Journalists may request a free PDF of this article by contacting jbardi@aip.org

NOTE: An image is available for journalists. Please contact jbardi@aip.org

CAPTION: This image shows the photocurrent from the nanowire detector (the yellow spot represents the region where current is generated under illumination) and the electrical contacts are indicated in blue, while the nanowire is indicated in green.

ABOUT APPLIED PHYSICS LETTERS

Applied Physics Letters, published by the American Institute of Physics, features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, Applied Physics Letters offers prompt publication of new experimental and theoretical papers bearing on applications of physics phenomena to all branches of science, engineering, and modern technology. Content is published online daily, collected into weekly online and printed issues (52 issues per year). See: http://apl.aip.org/

ABOUT AIP

The American Institute of Physics is a federation of 10 physical science societies representing more than 135,000 scientists, engineers, and educators and is one of the world's largest publishers of scientific information in the physical sciences. Offering partnership solutions for scientific societies and for similar organizations in science and engineering, AIP is a leader in the field of electronic publishing of scholarly journals. AIP publishes 12 journals (some of which are the most highly cited in their respective fields), two magazines, including its flagship publication Physics Today; and the AIP Conference Proceedings series. Its online publishing platform Scitation hosts nearly two million articles from more than 185 scholarly journals and other publications of 28 learned society publishers.

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Robot arm improves performance of brain-controlled device

2010-12-15

The performance of a brain-machine interface designed to help paralyzed subjects move objects with their thoughts is improved with the addition of a robotic arm providing sensory feedback, a new study from the University of Chicago finds. Devices that translate brain activity into the movement of a computer cursor or an external robotic arm have already proven successful in humans. But in these early systems, vision was the only tool a subject could use to help control the motion. Adding a robot arm that provided kinesthetic information about movement and position ...

Attempting to predict epileptic seizure

2010-12-15

Washington, D.C. (December 14, 2010) -- While the causes of epileptic seizures continue to confound brain researchers, scientists have been exploring how changes in the coordinated activity of brain networks, as monitored through electrodes, might help predict impending seizures. A report in the American Institute of Physics' journal CHAOS offers new insight into this possibility. Two properties are commonly used to measure fluctuations in the activity of a brain network; one, known as L, relates to the overall connectedness between the activities of brain regions (or ...

Qatar-led international team finds its first alien world

2010-12-15

In an exciting example of international collaboration, a Qatar astronomer teamed with scientists at the Harvard-Smithsonian Center for Astrophysics (CfA) and other institutions to discover a new alien world. This "hot Jupiter," now named Qatar-1b, adds to the growing list of alien planets orbiting distant stars. Its discovery demonstrates the power of science to cross political boundaries and increase ties between nations. "The discovery of Qatar-1b is a great achievement - one that further demonstrates Qatar's commitment to becoming a leader in innovative science and ...

Unique orangutan reintroduction project under imminent threat

2010-12-15

JAMBI, Indonesia – A Sumatran rainforest named a global priority for tigers and home to a unique orangutan rescue project is targeted for clearcutting by one of the world's largest paper suppliers. An investigation found that since 2004, companies affiliated with Asia Pulp & Paper/Sinar Mas Group have sought out selective logging concessions with dense natural forests in the Bukit Tigapuluh landscape. The companies obtained government licenses to switch the forest status to industrial timber plantation concessions, sometimes under legally questionable circumstances. ...

UA engineering tests underground border security system

2010-12-15

TUCSON, Ariz. (Dec. 14, 2010) -- A unique underground surveillance system tested by UA researchers could be used to watch the entire U.S.-Mexico border continuously. The border-monitoring system, known as Helios, consists of laser pulses transmitted through fiber-optic cables buried in the ground that respond to movements on the surface above. A detector at one or both ends of the cable analyzes these responses. Helios is sensitive enough to detect a dog and can discriminate between people, horses and trucks. The system can be set to avoid being triggered by small animals, ...

Vaccine boosts your immune system

2010-12-15

YOUR BODY'S OWN VACCINE: Researchers at BRIC, the University of Copenhagen, have discovered for the first time a protein normally found in the body that can act to prevent chronic tissue inflammation. When administered in the form of a therapeutic vaccine it is able to effectively prevent and treat a number of different inflammatory disease models for multiple sclerosis (MS), rheumatoid arthritis (RA), skin hypersensitivity and allergic asthma (AA). The article, entitled, "Endogenous collagen peptide activation of CD1d-restricted NKT cells ameliorates multiple tissue-specific ...

The AVE pollutes 29 percent less than traditional trains

2010-12-15

High-speed trains consume 29% less energy than conventional trains per passenger transported, and reduce CO2 emissions by the same proportion. These are the conclusions of a study by the Spanish Railways Foundation published in the journal Transportation Research Record. "A high speed train operating in normal conditions consumes less energy and produces less CO2 emissions per passenger transported (on average 29% less) than a conventional train travelling between the same two points at a lower speed", Alberto García, author of the study and a researcher at the Spanish ...

New asthma research breaks the mold

2010-12-15

Scientists investigating the allergic reactions that asthmatics suffer towards a common mould have discovered that many people with asthma actually had the mould growing in their own lungs. The research led by University of Leicester scientists at Glenfield Hospital has been published in the December 2010 issue of the American Journal of Respiratory and Critical Care Medicine. The team based in the Institute for Lung Health at the University of Leicester and Glenfield Hospital examined the impact on asthmatics of a common environmental mould, Aspergillus fumigates, ...

Scientists identify how virus triggers cervical and mouth cancer

2010-12-15

University of Manchester scientists have discovered for the first time an important new way in which the human papilloma virus (HPV) triggers cancer in what could lead to new treatments for cervical and mouth cancer. HPV infection is known to increase the risk of developing cancers of the cervix and mouth with the two high-risk forms of the virus accounting for approximately 70% of all cervical cancer cases. Vaccinations against these high-risk forms of HPV should reduce the incidence of cervical cancer but the frequency of mouth cancer actually increased in the UK ...

More than 25 percent of teenagers have suffered cyber bullying in the past year

2010-12-15

Cyber bullying is an emerging phenomenon that is becoming increasingly common among teenagers. Research by the University of Valencia (UV), based on a study carried out in the region, shows that between 25% and 29% of all teenagers have been bullied via their mobile phone or the internet over the past year. "The data from our study shows that technological bullying affects 24.6% of teenagers in the case of mobile telephony, and 29% with regard to the internet. In the large majority of cases, this abuse lasts for a month or less", Sofía Buelga, co-author of the study and ...

The threat of polio paralysis may have disappeared, but enterovirus paralysis is just as dangerous and surveillance and testing systems are desperately needed

Study shows ChatGPT failed when challenging ESCMID guideline for treating brain abscesses

Study finds resistance to critically important antibiotics in uncooked meat sold for human and animal consumption

Global cervical cancer vaccine roll-out shows it to be very effective in reducing cervical cancer and other HPV-related disease, but huge variations between countries in coverage

Personalised “cocktails” of antibiotics, probiotics and prebiotics hold great promise in treating a common form of irritable bowel syndrome, pilot study finds

Single quantum dot nanowire photodetectors

ELSE PRESS RELEASES FROM THIS DATE:

LAST 30 PRESS RELEASES: