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Feb 28

Reported by Evan Lerner, in University of Pennsylvania News, 22 Feb. 2012.

The technological world of the 21st century owes a tremendous amount to advances in electrical engineering, specifically, the ability to finely control the flow of electrical charges using increasingly small and complicated circuits. And while those electrical advances continue to race ahead, researchers at the University of Pennsylvania are pushing circuitry forward in a different way, by replacing electricity with light.

“Looking at the success of electronics over the last century, I have always wondered why we should be limited to electric current in making circuits,” said Nader Engheta, professor in the electrical and systems engineering department of Penn’s School of Engineering and Applied Science. “If we moved to shorter wavelengths in the electromagnetic spectrum — like light — we could make things smaller, faster and more efficient.”

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Feb 26

Reported by , in Wired Science, 22 Feb. 2012.

The sensational result that neutrinos can travel faster than the speed of light may be undone by nothing more than a simple mechanical error.

Scientists from the OPERA collaboration at the Gran Sasso National Laboratory in Italy have “identified two issues that could significantly affect the reported result,” wrote OPERA spokesman Antonio Ereditato in an email.

The first issue is a faulty connection of the fiber-optic cable bringing the GPS signal to the experiment’s master clock. The experiment’s GPS may also have been providing the wrong timestamps during synchronization between events.

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Feb 24

Reported by Newswise, Georgia Institute of Technology, 17/2/2012.

Imagine if smartphone and tablet users could text a note under the table during a meeting without anyone being the wiser. Mobile gadget users might also be enabled to text while walking, watching TV or socializing without taking their eyes off what they’re doing.

Georgia Tech researchers have built a prototype app for touch-screen mobile devices that is vying to be a complete solution for texting without the need to look at a mobile gadget’s screen.

“Research has shown that chorded, or gesture-based, texting is a viable solution for eyes-free written communication in the future, making obsolete the need for users to look at their devices while inputting text on them,” said Mario Romero, Postdoctoral Fellow in the School of Interactive Computing (IC) and the project’s principal investigator. Continue reading »

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Feb 23

By Martin Fuechsle, Jill A. Miwa, Suddhasatta Mahapatra, Hoon Ryu, Sunhee Lee, Oliver Warschkow, Lloyd C. L. Hollenberg, Gerhard Klimeck & Michelle Y. Simmons in Nature Nanotechnology (2012), Published online, 19 February 2012.

Abstract: The ability to control matter at the atomic scale and build devices with atomic precision is central to nanotechnology. The scanning tunnelling microscope1 can manipulate individual atoms2 and molecules on surfaces, but the manipulation of silicon to make atomic-scale logic circuits has been hampered by the covalent nature of its bonds. Resist-based strategies have allowed the formation of atomic-scale structures on silicon surfaces3, but the fabrication of working devices—such as transistors with extremely short gate lengths4, spin-based quantum computers5, 6, 7, 8 and solitary dopant optoelectronic devices9—requires the ability to position individual atoms in a silicon crystal with atomic precision. Here, we use a combination of scanning tunnelling microscopy and hydrogen-resist lithography to demonstrate a single-atom transistor in which an individual phosphorus dopant atom has been deterministically placed within an epitaxial silicon device architecture with a spatial accuracy of one lattice site. The transistor operates at liquid helium temperatures, and millikelvin electron transport measurements confirm the presence of discrete quantum levels in the energy spectrum of the phosphorus atom. We find a charging energy that is close to the bulk value, previously only observed by optical spectroscopy.

Read more in doi:10.1038/nnano.2012.21.

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