Graphene-based discs ensure safe storage


Graphene-based discs ensure safe storage

(Phys.org) —Swinburne University of Technology researchers have shown the potential of a new material for transforming secure optical information storage.

In their latest research paper published in Scientific Reports, researchers Xiangping Li, Qiming Zhang, Xi Chen and Professor Min Gu demonstrated the potential to record holographic coding in a polymer composite.

“Conventionally, information is recorded as binary data in a disc. If the disc is broken, the information cannot be retrieved,” Director of the Centre for Micro-Photonics at Swinburne, Professor Min Gu, said.

“This is a major operation cost in big data centres, which consist of thousands of disc arrays with multiple physical duplicates of data. The new material allows the development of super-discs, which will enable information to be retrieved – even from broken pieces.”

Graphene oxide is similar to graphene, discovered by Andre Geim and Konstantin Novoselov, who received the 2010 Nobel Prize in Physics for this groundbreaking discovery. Graphene is very strong, light, flexible, nearly transparent, and is an excellent conductor of heat and electricity.

Graphene oxide has similar properties, but also has a fundamental fluorescent property that can be used in bioimaging and for multimode optical recording.

By focusing an ultrashort laser beam onto the graphene oxide polymer, the researchers created a 10-100 times increase in the of the graphene oxide along with a decrease in its fluorescence. (The refractive index is the measure of the bending of light as it passes through a medium.)

“The unique feature of the giant refractive-index modulation together with the fluorescent property of the graphene oxide polymer offers a new mechanism for multimode optical recording,” Professor Gu said.

To demonstrate the feasibility of the mechanism, the researchers encoded the image of a kangaroo in a computer generated hologram. The hologram was then rendered as a three-dimensional recording to the graphene oxide polymer. The encrypted patterns in the hologram could not be seen as a normal microscope image, but could be retrieved in the diffracted mode.

“The giant refractive index of this material shows promise for merging data storage with holography for security coding,” Professor Gu said.

“This exciting feature not only boosts the level of storage security, but also helps to reduce the operation costs of big data centres that rely on multiple physical duplicates to avoid data loss.”

The researchers say it could also revolutionise flat screen TV and solar cell technology.

“More importantly, graphene has been deemed as a revolutionary replacement for silicon, which is the platform for current information technologies based on electronics,” Dr Xiangping Li said.

“The giant refractive index we discovered shows the promise of to merge electronics and photonics for the platform of the next generation information technologies.”

Read more at: http://phys.org/news/2013-10-graphene-based-discs-safe-storage.html#jCp

Read more at: http://phys.org/news/2013-10-graphene-based-discs-safe-storage.html#jCp

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Nobel physics prize highlights weird world of quantum optics


By Karl Ritter and Louise Nordstrom

Image: Atomic clock

STOCKHOLM — A French-American duo shared the 2012 Nobel Prize in physics Tuesday for inventing methods to observe the bizarre properties of the quantum world — research that has led to the construction of extremely precise clocks and helped scientists take the first steps toward building superfast computers.

Serge Haroche of France and American David Wineland opened the door to new experiments in quantum physics by showing how to observe individual quantum particles without destroying them.

A quantum particle is one that is isolated from everything else. In this situation, an atom or electron or photon takes on strange properties. It can be in two places at once, for example. It behaves in some ways like a wave. But these properties are instantly changed when it interacts with something else, such as when somebody observes it.

Working separately, the two scientists, both 68, developed “ingenious laboratory methods” that allowed them to manage and measure and control fragile quantum states, the Royal Swedish Academy of Sciences said.

“Their ground-breaking methods have enabled this field of research to take the very first steps towards building a new type of superfast computer based on quantum physics,” the academy said. “The research has also led to the construction of extremely precise clocks that could become the future basis for a new standard of time.”

Background: Nobel-winning physics explained

Haroche is a professor at the College de France and Ecole Normale Superieure in Paris. Wineland is a physicist at the National Institute of Standards and Technology and the University of Colorado in Boulder, Colorado.

The two researchers use opposite approaches to examine, control and count quantum particles, the academy said. Wineland traps ions — electrically charged atoms — and measures them with light. Haroche controls and measures photons, or light particles, by sending atoms through a specially prepared trap.

Haroche said he was out walking with his wife when he got the call from the Nobel judges.

“I was in the street and passing a bench so I was able to sit down,” Haroche told a news conference in Stockholm by telephone. “It’s very overwhelming.”

He said his work in the realm of quantum physics could ultimately lead to unimaginably fast computers, with atoms that can essentially be in two different states at the same time. “You can do things which are prohibited by the laws of classical physics,” he told The Associated Press.

Haroche also said quantum research could help make GPS navigating systems more accurate.

‘Field of Dweebs’

NIST spokesman Jim Burrus said Wineland was asleep at home in Boulder when the call came in early Tuesday notifying him that he won; his wife answered the phone. Burrus said Wineland described the news as overwhelming and wonderful.

He said Wineland was a humble person who never expected to win prizes. He also doesn’t take himself very seriously: Wineland once played first base on a NIST softball team called “Field of Dweebs.”

Christopher Monroe, who does similar work at the Joint Quantum Institute at the University of Maryland, said the awarding of the prize to the two men “is not a big surprise to me. … It was sort of obvious that they were a package.”

Monroe said that thanks to the bizarre properties of the quantum world, when he and Wineland worked together in the 1990s, they were able to put a single atom in two places simultaneously.

At that time, it wasn’t clear that trapping single atoms could help pave the way to superfast quantum computers, he said. That whole field “just fell into our laps,'” Monroe said.

In an ordinary computer, information is represented in bits, each of which is either a zero or a one. But in a quantum computer, an individual particle can essentially represent a zero and a one at the same time — that is, until the result is read out. If scientists can make quantum bits, or “qubits,” work together, certain kinds of calculations could be done with blazing speed.

One example is prime factorization, the process of discovering which two prime numbers can be multiplied together to produce a given number. That has implications for breaking the encryption codes that provide the foundation for today’s secure financial transactions. However, quantum encryption could open the way for a new generation of secure communication tools as well.

Quantum computers could radically change people’s lives in the way that classical computers did last century, but a full-scale quantum computer is still decades away, the Nobel judges said. “The calculations would be incredibly much faster and exact, and you would be able to use it for areas like meteorology and for measuring the climate of the earth,” said Lars Bergstrom, the secretary of the prize committee.

The physics prize was the second of the 2012 Nobel Prizes to be announced, with the medicine prize going Monday to stem cell pioneers John Gurdon of Britain and Japan’s Shinya Yamanaka. Each award is worth 8 million kronor, or about $1.2 million.

The prizes are always handed out on Dec. 10, the anniversary of prize founder Alfred Nobel’s death in 1896.