Scientific Frontline® On-Site Search Engine by Google Co-op

Current UTC Time
 
News Home, where you will find the "Current Top Stories"The Communication Center contains current news briefs from major Universities, NASA, ESA, and the top three Aviation Mfg.Science section contains all the latest knowledge in Medical Research, Archeology, Biology, and other General Science NewsCurrent Earth Science and Environmental discoveries.The E.A.R., Environmental Awareness Report. E.A.R. will keep you advised of Environmental Alerts, Government, University, and public projects. All the current space discoveries from Hubble, Spitzer, Chandra X-Ray, ESO, Gemini, Subaru, ESA, NASA, and many more. The latest in space theories from leading astronomers and scientist from around the world.The Space Weather Forecast Center by Scientific Frontline, Current up-to-date space weather, forecasts, alerts and warnings. Images from SOHO, GOES, and STEREO. Plus solar observations from Erika RixCurrent space missions newsThe Cassini Main Page. Containing all the latest news from the Cassini Spacecraft around Saturn. Leading into Cassini status reports, The Cassini Gallery of all the latest images from Cassini. Seeing Saturn and all her moons like never before.Daily Sky maps, Celestial Events Calendar.Observatories Gallery, images from The Great Observatories and other leaders in astronomy.The Stellar Nights  Gallery, An amateur astronomical collection from John Crilly, Richard Handy, Erika Rix, and Paul RixCloudy Nights Telescope Reviews / An Atronomical Community.The latest in Computer, Nanotechnology, and General Technological advancements.The latest in Aviation achievements in civil, military, and space aviationThe World News Report,  news from the Voxant Viral Syndication, known as the Newsroom. Contains the latest videos from major news sources.The news archive from Scientific Frontline's past articles. A world of knowledge at your fingertips.Abstracts, Journals, and Technical papers maintained by Scientific Frontline. The Gateway to all the galleries in the Scientific Frontline collectionThe Scientific Frontline Discussion Rooms. Open to the public.upcoming events, seminars, and lectures from major universities, government, and privately sponsored programsSite Related links from major universities, government and private research labs.Assorted Downloads related to space, science, aviation, including screensavers and ASTROMONY SOFTWARE, and other endorsed programs.Words from Heidi-Ann Kennedy, Director Scientific FrontlineThe foundation of an online publication by SFL ORG. News Network called Scientific FrontlineContact page to Scientific Frontline / SFL ORG. News NetworkDisclaimer / Legal Notice for use of the SFL ORG. News Network's publication Scientific Frontline
an online publication of the SFL ORG. Educational News Network

Scientists Store and Retrieve Data Inside an Atom

Friday, October 24, 2008

Another step towards quantum computing was taken when a team of scientists processed information in the electron spin (blue) and stored it in the nuclear spin (yellow) of phosphorus atoms through a combination of microwave and radio-frequency pulses.

Credit: Flavio Robles, Berkeley Lab Public Affairs
Another step towards quantum computing – the Holy Grail of data processing and storage – was achieved when an international team of scientists that included researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) were able to successfully store and retrieve information using the nucleus of an atom.

In a paper entitled: “Solid-state quantum memory using the 31P nuclear spin,” published in the October 23 issue of the journal Nature, the team described an experiment in which exceptionally pure and isotopically controlled crystals of silicon were precisely doped with phosphorus atoms. Quantum information was processed in phosphorus electrons, transferred to phosphorus nuclei, then subsequently transferred back to the electrons. This is the first demonstration that a single atomic nucleus can serve as quantum computational memory.

John Morton of Oxford University was the lead author. Co-authoring the paper from Berkeley Lab were Thomas Schenkel, Eugene Haller and Joel Ager. Other co-authors were Richard Brown, Brendon Lovett and Arzhang Ardavan of Oxford University, and Alexei Tyryshkin, Shyam Shankar and Stephen Lyon, of Princeton, University.

The immediate lure of quantum computing is blinding speed: a quantum computer would be able to perform certain mathematical tasks, such as factoring, many billions of times faster than the most powerful supercomputers of today. Beyond that, quantum computing should make it possible to engage calculations that cannot be considered with current “classical” computing technology. The secret behind quantum computing is the weird, counterintuitive but demonstrably real properties of quantum mechanics.

In classical computing, information is processed and stored based on the charge of an electron, and represented in a binary digit or “bit.” Each bit carries a value of 0 (no charge) or 1 (charge). Quantum computing utilizes an intrinsic quantum property called “spin,” in which certain particles can act as if they were tiny bar magnets. Spin is assigned a directional state of either “up” or “down,” which can be used to encode data in 0s and 1s. However, unlike charge in classical computing, which is either present or not, spin can be up, down or both, thanks to a quantum effect called “superposition.”

Superpositioning exponentially expands the storage capabilities of a quantum data bit or “qubit.” Whereas a byte of classical data, made up of three bits, can represent only one of the eight possible combinations of 0s and 1s, a quantum equivalent (sometimes called a qubyte) can represent all eight combinations at once. Furthermore, thanks to another quantum property called “entanglement,” operations on all eight combinations can be performed simultaneously.

Of the many challenges facing quantum computing, one of the biggest has been finding a way to preserve the integrity of data while it is stored. Although the spin of electrons has proven well-suited for data processing, it is too fragile to be used as memory – the data quickly becomes corrupted by the influence of other electrons. To overcome this obstacle, the co-authors of this experiment turned to the more protected environs of the atomic nucleus.

In this exciting collaboration with colleagues from Oxford and Princeton, we have reported on a very important demonstration of coherent information transfer between the electron spin (processing qubit) and the nuclear spin (memory qubit) of phosphorus atoms in isotopically enriched silicon crystals,” said co-author Schenkel, a physicist in Berkeley Lab’s Accelerator and Fusion Research Division, who has been a leader in the use of ion beams for the development of quantum computer test structures.

The electron spin information was faithfully stored in the nuclear spin for nearly two seconds (thousands of times longer than ever reported for similar studies), then transferred back to the electron spin with about 90-percent fidelity,” Schenkel said.

In this study, the co-authors created a superposition state in electron spin and transferred it to nuclear spin using a combination of microwave and radio-frequency pulses, which they applied to phosphorus-31. This stable isotope of phosphorus is the ideal electron donor for silicon-28, the stable isotope of silicon that is the basis for today’s computer technology. Said lead author Morton in a statement, “The electron acts as a middle-man between the nucleus and the outside world. It gives us a way to have our cake and eat it - fast processing speeds from the electron, and long memory times from the nucleus.”

Crucial to the success of this study were the exceptionally pure silicon-28 crystals created by co-authors Haller and Ager. Haller is a world authority on crystal growth and purification and is credited with launching the modern era of isotopically enriched semiconductor research. Ager designed and built a one-of-its-kind reactor for creating isotopically enriched and chemically pure silicon, featuring a high conversion efficiency.

Said Haller, “Crystals of natural silicon contain 4.7-percent of the isotope silicon-29, in addition to silicon-28 and silicon-30. For this study we needed silicon crystals that were not only chemically pure, but isotopically pure as well because silicon-29 has a nuclear spin that would interfere with the readout of the electron and nuclear spins of the phosphorus.”

Since the silicon crystals to be doped would consist of billions of atoms, creating isotopically pure crystals of silicon-28 was a painstaking process. Once these exceptionally pure crystals were created, they then had to be doped with phosphorus-31 in specific areas of the crystal and to just the right amount – an undertaking that Ager compared to adding one extra person to Earth’s population at one particular address.

Now that it has been demonstrated that electron spin data can be stored and retrieved via nuclear spin, future steps will require improving spin control and readout mechanisms. Also, while the quantum memory time observed in this study is exceptionally long by previous standards, it should still be possible to significantly extend this time.

The good news is that there are no know physical limits that would prevent quantum memory time in nuclear spin from being longer,” said Ager. “With even greater isotopic and chemical purity of our silicon crystals, we should be able to store data in the nucleus for an arbitrarily long period of time, maybe even in terms of years.”

The Berkeley Lab portion of this research was supported in part by the U.S. Department of Energy’s Office of Science, through the Materials Sciences and Engineering Division of its Basic Energy Sciences programs, and in part
by the National Security Agency.

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California.

Source: Lawrence Berkeley National Laboratory

AddThis Social Bookmark Button

Scientific Frontline®
RSS Feeds

Scientific Frontline®
The Comm Center
The E.A.R.®
World News Report
Stellar Nights®
Cassini Gallery
Mars Gallery
Missions Gallery
Observatories Gallery
Observatories Gallery
Space Weather Alerts
Events
Directors Chair

Scientific Frontline®
Is supported in part by
Readers Like You”
 
Denser computer chips possible with plasmonic lenses that 'fly' Good Code, Bad Computations: a Computer Security Gray Area Quantum computing breakthrough arises from unknown molecule Navigate Back or Forward Through Technology News, Related Page or Pick an Article From The News Ticker.


Scientific Frontline®, Stellar Nights®, E.A.R.®, and Environmental Awareness Report®”
Are Registered Trademarks of the
Online Publication of the SFL ORG. Educational News Network
Oklahoma City, Oklahoma USA
A Not-for-Profit Educational News Service
© 2005 - 2008 All Rights Reserved


Home | Comm. Center | Science | Earth Science | Space | Space Weather Center | Aviation | Technology | Galleries | About Us | Contact Us | Site Map | FAQ