Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print Fast quantum computer building block created

Fast quantum computer building block created

August 21, 2008

ANN ARBOR, Mich.---The fastest quantum computer bit that exploits the main advantage of the qubit over the conventional bit has been demonstrated by researchers at University of Michigan, U.S. Naval Research Laboratory and the University of California at San Diego.

The scientists used lasers to create an initialized quantum state of this solid-state qubit at rates of about a gigahertz, or a billion times per second. They can also use lasers to achieve fundamental steps toward programming it.




A conventional bit can be a 0 or a 1. A quantum bit, or qubit, can be both at the same time. Until now, scientists couldn't stabilize that duality.

Physics professor Duncan Steel, doctoral student Xiaodong Xu and their colleagues used lasers to coherently, or stably, trap the spin of one electron confined in a single semiconductor quantum dot. A quantum dot is like a transistor in a conventional computer.

The scientists trapped the spin in a dark state in which they can arbitrarily adjust the amount of 0 and 1 the qubit represents. They call this state "dark" because it does not absorb light. Therefore, light does not cause loss of coherence between the two states. In other words, the light does not destabilize the qubit. A paper on these findings will be published in Nature Physics and is available early in the online edition.

"We are the first to show that you can do this to a single electron in a self-assembled quantum dot," Steel said. "If you're going to do quantum computing, you have to be able to work with one electron at a time."

Spin is an intrinsic property of the electron that isn't a real rotation. Steel compares it to the magnetic poles. Electrons are said to have spin up or down. In quantum computing, the up and down directions represent the 0s and 1s of conventional computing.

Steel's approach to developing a quantum computer is to use ultrafast lasers to manipulate arrays of semiconductor quantum dots, each containing one electron. Quantum logic gates are formed by quantum mechanical interactions between the dots.

Previously in Steel's lab, researchers have used a laser to produce an electron in a state representative of a 1 or a 0 and a small amount of the other state. Now, using two laser frequencies, they have trapped it as a 0 and a 1 at the same time, and they can adjust the amount of each.

Because the electron is trapped in a dark state, applied light can't destroy the coherence. Energy from light can flip the spin of electrons, or quantum bits, which would jumble any information being stored in the bit.

"This dark state is a place where information can be stored without any error," Steel said.

Because of their ability to represent multiple states simultaneously, quantum computers could theoretically factor numbers dramatically faster and with smaller computers than conventional computers. For this reason, they could vastly improve computer security.

"The National Security Agency has said that based on our present technology, we have about a 20-year window of security," Steel said. "That means if we sent up a satellite today, it would take somebody about 20 years to crack the code. Quantum computers will let you develop a code that would be impossible to crack with a conventional computer."

Physicists achieved this by using two continuous wave lasers.

University of Michigan



Related Quantum Computer Current Events and Quantum Computer News Articles Quantum Computer Current Events and Quantum Computer News RSS Quantum Computer Current Events and Quantum Computer News RSS
NIST demonstrates 'universal' programmable quantum processor
Physicists at the National Institute of Standards and Technology (NIST) have demonstrated the first "universal" programmable quantum information processor able to run any program allowed by quantum mechanics-the rules governing the submicroscopic world-using two quantum bits (qubits) of information.

Field experiment on a robust hierarchical metropolitan quantum cryptography network
Key Laboratory of Quantum Information (CAS), University of Science and Technology of China has recently demonstrated a metropolitan Quantum Cryptography Network (QCN) for Government Administration in Wuhu, China. Because of its scientific significance and social impact, the project is reported in Volume 54, Issue 17 (September, 2009) of the Chinese Science Bulletin authored by Fang-xing Xu et al.

Diamonds may be the ultimate MRI probe, say Quantum physicists
Diamonds, it has long been said, are a girl's best friend. But a research team including a physicist from the National Institute of Standards and Technology (NIST) has recently found that the gems might turn out to be a patient's best friend as well.

Experiments at UCSB push quantum mechanics to higher levels
Scientists at UC Santa Barbara have devised a new type of superconducting circuit that behaves quantum mechanically -- but has up to five levels of energy instead of the usual two. The findings are published in the August 7 issue of Science.

A Police Woman Fights Quantum Hacking and Cracking
The first desktop computers changed the way we managed data forever. Three decades after their introduction, we rely on them to manage our time, social life and finances - and to keep this information safe from prying eyes and online predators.

Physicists find way to control individual bits in quantum computers
Physicists at the National Institute of Standards and Technology (NIST) have overcome a hurdle in quantum computer development, having devised* a viable way to manipulate a single "bit" in a quantum processor without disturbing the information stored in its neighbors.

Scientists create first electronic quantum processor
A team led by Yale University researchers has created the first rudimentary solid-state quantum processor, taking another step toward the ultimate dream of building a quantum computer.

Manipulating light on a chip for quantum technologies
A team of physicists and engineers at Bristol University has demonstrated exquisite control of single particles of light - photons - on a silicon chip to make a major advance towards long-sought-after quantum technologies, including super-powerful quantum computers and ultra-precise measurements.

NIST physicists demonstrate quantum entanglement in mechanical system
Physicists at the National Institute of Standards and Technology (NIST) have demonstrated entanglement-a phenomenon peculiar to the atomic-scale quantum world-in a mechanical system similar to those in the macroscopic everyday world.

UCSB researchers describe breakthrough in the quantum control of light
Researchers at UC Santa Barbara have recently demonstrated a breakthrough in the quantum control of photons, the energy quanta of light.
More Quantum Computer Current Events and Quantum Computer News Articles
An Introduction to Quantum Computing

An Introduction to Quantum Computing
by Phillip Kaye (Author), Raymond Laflamme (Author), Michele Mosca (Author)

This concise, accessible text provides a thorough introduction to quantum computing - an exciting emergent field at the interface of the computer, engineering, mathematical and physical sciences. Aimed at advanced undergraduate and beginning graduate students in these disciplines, the text is technically detailed and is clearly illustrated throughout with diagrams and exercises. Some prior knowledge of linear algebra is assumed, including vector spaces and inner products. However, prior familiarity with topics such as tensor products and spectral decomposition is not required, as the necessary material is reviewed in the text.

A Shortcut Through Time: The Path to the Quantum Computer

A Shortcut Through Time: The Path to the Quantum Computer
by George Johnson (Author)

In this remarkably illustrative and thoroughly accessible look at one of the most intriguing frontiers in science and computers, award-winning New York Times writer George Johnson reveals the fascinating world of quantum computing—the holy grail of super computers where the computing power of single atoms is harnassed to create machines capable of almost unimaginable calculations in the blink of an eye.

As computer chips continue to shrink in size, scientists anticipate the end of the road: A computer in which each switch is comprised of a single atom. Such a device would operate under a different set of physical laws: The laws of quantum mechanics. Johnson gently leads the curious outsider through the surprisingly simple ideas needed to understand this dream, discussing the...

James Bond 007: Quantum of Solace

James Bond 007: Quantum of Solace
by Activision

Can you be the next James Bond? Coldly efficient dangerous the new Bond is the ultimate weapon in today's ruthless world of international espionage. Blending first person shooting and third person action, Quantum of Solace puts you in control of Bond's greatest weapon his mind. You must think like Bond and intelligently use the map and situation to your advantage. Confront enemies in a variety of ways: take them head on, fire from behind cover or sneak up silently and eliminate them with a variety of special takedown moves. Based on Quantum of Solace and Casino Royale, Quantum of Solace the Game puts you in the dangerous world of international espionage and intrigue.



Quantum Leap -  The Complete Fourth Season

Quantum Leap - The Complete Fourth Season
Starring: Scott Bakula, Dean Stockwell, Candi Brough, Randi Brough, Christine Cattell
Directed By: Anita W. Addison, Bob Hulme, Chris Ruppenthal, Eric Laneuville, James Whitmore Jr.

Take a trip through time with the daring Dr. Sam Beckett (Scott Bakula) and his hilarious hologram guide, Al (Dean Stockwell), in all 22 extraordinary, groundbreaking episodes of Quantum Leap: The Complete Fourth Season. It’s adventure like you’ve never seen, with each amazing episode from this eight-time Emmy-nominated season now digitally remastered for incredible picture quality. Journey back as Sam and Al survive a hurricane, trail a murderer, make a monkey out of themselves and even switch roles! With each "leap" into another identity, Sam hopes to find some insight into the jump that will finally take him home. And now, fans can spend more time with Sam and Al with an exclusive bonus episode from the Fifth Season. You won’t want to miss a minute of the adventure!

LeapFrog Quantum Pad Learning System

LeapFrog Quantum Pad Learning System
by LeapFrog

This educational product helps children in 3rd to 5th grade learn fundamental skills and explore topics that interest them the most. Each book (sold separately) is packed with engaging activities, games, stories and facts that fascinate kids. The Quantum Pad Learning System features engaging audio, games, activities and quizzes that make learning fun. It comes with an interactive sampler book of the Quantum Pad library. Other Quantum Pad Interactive Books and Cartridges sold separately. As an added bonus, this system also works with all LeapPad books and cartridges (sold separately). Requires 4 "AA" alkaline batteries (not included).

Optical Quantum OQPDPRDL08WIP DVD+R DL Spindle - 50 Pack, White Inkjet HUB Printable

Optical Quantum OQPDPRDL08WIP DVD+R DL Spindle - 50 Pack, White Inkjet HUB Printable
by Optical Quantum

Get almost twice the storage capacity of standard DVDs with these Optical Quantum OQPDPRDL08WIP DVD+R DL discs

Quantum of Solace

Quantum of Solace
David Arnold (Composer)

Quantum of Solace continues the high octane adventures of Daniel Craig as James Bond. Directed by Marc Fisher, this 22nd installation in the 007 franchise hits theaters on October 31st, 2008 in Europe and November 14th in the US. This film features music by composer David Arnold and the new single 'Another Way To Die' by Jack White (White Stripes) and Alicia Keys, a first ever duet for a James Bond flick. The Quantum of Solace soundtrack will include the movie score and this new single. David Arnold is a Grammy-winning English film composer, best known for scoring five James Bond films including the score for Casino Royale and the blockbuster Independence Day.

Quantum Computing for Computer Scientists

Quantum Computing for Computer Scientists
by Noson S. Yanofsky (Author), Mirco A. Mannucci (Author)

The multidisciplinary field of quantum computing strives to exploit some of the uncanny aspects of quantum mechanics to expand our computational horizons. Quantum Computing for Computer Scientists takes readers on a tour of this fascinating area of cutting-edge research. Written in an accessible yet rigorous fashion, this book employs ideas and techniques familiar to every student of computer science. The reader is not expected to have any advanced mathematics or physics background. After presenting the necessary prerequisites, the material is organized to look at different aspects of quantum computing from the specific standpoint of computer science. There are chapters on computer architecture, algorithms, programming languages, theoretical computer science, cryptography, information...

Learning Resources - Quantum  Big Screen Microscope

Learning Resources - Quantum Big Screen Microscope
by Learning Resources

This big seven-inch screen microscope projects a whopping 10x, 20x, or 40x clear image. Includes assortment of accessories, glare-reducing shield and Snap-Tight tray to hold components. Operates with three "C" batteries (not included) or AC adapter (sold separately).

Quantum Superloader 3 Eight-cartridge LTO Magazine Include One Eight-cartridge M

Quantum Superloader 3 Eight-cartridge LTO Magazine Include One Eight-cartridge M
by Quantum Chemical

When you need simplicity, reliability and the most value for your money in a tape autoloader, the Quantum SuperLoader is the right choice. Whether you want to keep up with application data growth, replace older units within your existing infrastructure or implement a new application, it offers technological excellence you can afford - from the worldwide leader in autoloader systems.

© 2009 BrightSurf.com