Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Princeton scientist makes a leap in quantum computing

Jason Petta, an assistant professor of physics, has found a way to alter the property of a lone electron without disturbing the trillions of electrons in its immediate surroundings. Such a feat is an important step toward developing future types of quantum computers. (Photos: Brian Wilson)
Jason Petta, an assistant professor of physics, has found a way to alter the property of a lone electron without disturbing the trillions of electrons in its immediate surroundings. Such a feat is an important step toward developing future types of quantum computers. (Photos: Brian Wilson)

Abstract:
A major hurdle in the ambitious quest to design and construct a radically new kind of quantum computer has been finding a way to manipulate the single electrons that very likely will constitute the new machines' processing components or "qubits."

Princeton scientist makes a leap in quantum computing

Princeton, NJ | Posted on February 7th, 2010

Princeton University's Jason Petta has discovered how to do just that -- demonstrating a method that alters the properties of a lone electron without disturbing the trillions of electrons in its immediate surroundings. The feat is essential to the development of future varieties of superfast computers with near-limitless capacities for data.

Petta, an assistant professor of physics, has fashioned a new method of trapping one or two electrons in microscopic corrals created by applying voltages to minuscule electrodes. Writing in the Feb. 5 edition of Science, he describes how electrons trapped in these corrals form "spin qubits," quantum versions of classic computer information units known as bits. Other authors on the paper include Art Gossard and Hong Lu at the University of California-Santa Barbara.

Previous experiments used a technique in which electrons in a sample were exposed to microwave radiation. However, because it affected all the electrons uniformly, the technique could not be used to manipulate single electrons in spin qubits. It also was slow. Petta's method not only achieves control of single electrons, but it does so extremely rapidly -- in one-billionth of a second.

"If you can take a small enough object like a single electron and isolate it well enough from external perturbations, then it will behave quantum mechanically for a long period of time," said Petta. "All we want is for the electron to just sit there and do what we tell it to do. But the outside world is sort of poking at it, and that process of the outside world poking at it causes it to lose its quantum mechanical nature."

When the electrons in Petta's experiment are in what he calls their quantum state, they are "coherent," following rules that are radically different from the world seen by the naked eye. Living for fractions of a second in the realm of quantum physics before they are rattled by external forces, the electrons obey a unique set of physical laws that govern the behavior of ultra-small objects.

Scientists like Petta are working in a field known as quantum control where they are learning how to manipulate materials under the influence of quantum mechanics so they can exploit those properties to power advanced technologies like quantum computing. Quantum computers will be designed to take advantage of these characteristics to enrich their capacities in many ways.

In addition to electrical charge, electrons possess rotational properties. In the quantum world, objects can turn in ways that are at odds with common experience. The Austrian theoretical physicist Wolfgang Pauli, who won the Nobel Prize in Physics in 1945, proposed that an electron in a quantum state can assume one of two states -- "spin-up" or "spin-down." It can be imagined as behaving like a tiny bar magnet with spin-up corresponding to the north pole pointing up and spin-down corresponding to the north pole pointing down.

An electron in a quantum state can simultaneously be partially in the spin-up state and partially in the spin-down state or anywhere in between, a quantum mechanical property called "superposition of states." A qubit based on the spin of an electron could have nearly limitless potential because it can be neither strictly on nor strictly off.

New designs could take advantage of a rich set of possibilities offered by harnessing this property to enhance computing power. In the past decade, theorists and mathematicians have designed algorithms that exploit this mysterious superposition to perform intricate calculations at speeds unmatched by supercomputers today.

Petta's work is using electron spin to advantage.

"In the quest to build a quantum computer with electron spin qubits, nuclear spins are typically a nuisance," said Guido Burkard, a theoretical physicist at the University of Konstanz in Germany. "Petta and coworkers demonstrate a new method that utilizes the nuclear spins for performing fast quantum operations. For solid-state quantum computing, their result is a big step forward."

Petta's spin qubits, which he envisions as the core of future quantum logic elements, are cooled to temperatures near absolute zero and trapped in two tiny corrals known as quantum wells on the surface of a high-purity, gallium arsenide chip. The depth of each well is controlled by varying the voltage on tiny electrodes or gates. Like a juggler tossing two balls between his hands, Petta can move the electrons from one well to the other by selectively toggling the gate voltages.

Prior to this experiment, it was not clear how experimenters could manipulate the spin of one electron without disturbing the spin of another in a closely packed space, according to Phuan Ong, the Eugene Higgins Professor of Physics at Princeton and director of the Princeton Center for Complex Materials.

Other experts agree.

"They have managed to create a very exotic transient condition, in which the spin state of a pair of electrons is in that moment entangled with an almost macroscopic degree of freedom," said David DiVincenzo, a research staff member at the IBM Thomas J. Watson Research Center in Yorktown Heights, N.Y.

Petta's research also is part of the fledgling field of "spintronics" in which scientists are studying how to use an electron's spin to create new types of electronic devices. Most electrical devices today operate on the basis of another key property of the electron -- its charge.

There are many more challenges to face, Petta said.

"Our approach is really to look at the building blocks of the system, to think deeply about what the limitations are and what we can do to overcome them," Petta said. "But we are still at the level of just manipulating one or two quantum bits, and you really need hundreds to do something useful."

As excited as he is about present progress, long-term applications are still years away. "It's a one-day-at-a-time approach," Petta said.

Research at Princeton was supported by the Sloan Foundation, the Packard Foundation and the National Science Foundation. Work at the University of California-Santa Barbara was supported by the Defense Advanced Research Projects Agency and the NSF.

####

About Princeton University
Princeton University is a vibrant community of scholarship and learning that stands in the nation's service and in the service of all nations. Chartered in 1746, Princeton is the fourth-oldest college in the United States. Princeton is an independent, coeducational, nondenominational institution that provides undergraduate and graduate instruction in the humanities, social sciences, natural sciences and engineering.

As a world-renowned research university, Princeton seeks to achieve the highest levels of distinction in the discovery and transmission of knowledge and understanding. At the same time, Princeton is distinctive among research universities in its commitment to undergraduate teaching.

Today, more than 1,100 faculty members instruct approximately 5,000 undergraduate students and 2,500 graduate students. The University's generous financial aid program ensures that talented students from all economic backgrounds can afford a Princeton education.

For more information, please click here

Contacts:
Office of Communications
Princeton University
22 Chambers Street, Suite 201
Princeton, N.J. 08542
Tel (609) 258-3601
Fax (609) 258-1301

Primary Media Contact:
Cass Cliatt
Director of Media Relations
(609) 258-6108

Copyright © Princeton University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Rutgers, NIST physicists report technology with potential for sub-micron optical switches March 31st, 2015

Prototype 'nanoneedles' generate new blood vessels in mice: Scientists have developed tiny 'nanoneedles' that have successfully prompted parts of the body to generate new blood vessels, in a trial in mice March 31st, 2015

Super sensitive measurement of magnetic fields March 31st, 2015

Nanomedicine pioneer Mauro Ferrari at ETH Zurich March 31st, 2015

Govt.-Legislation/Regulation/Funding/Policy

Rutgers, NIST physicists report technology with potential for sub-micron optical switches March 31st, 2015

SUNY Poly CNSE and Title Sponsor SEFCU Name Capital Region Teams Advancing to the Final Round of the 2015 New York Business Plan Competition March 30th, 2015

Princess Margaret scientists convert microbubbles to nanoparticles: Harnessing light to advance tumor imaging, provide platform for targeted treatment March 30th, 2015

Nanoscale worms provide new route to nano-necklace structures March 29th, 2015

Possible Futures

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Nanocomposites Market Growth, Industry Outlook To 2020 by Grand View Research, Inc. March 21st, 2015

Nanotechnology Drug Delivery Market in the US 2012-2016 : Latest Report Available by Radiant Insights, Inc March 16th, 2015

Spintronics

Magnetic vortices in nanodisks reveal information: Researchers from Dresden and Jülich use microwaves to read out information from smallest storage devices March 4th, 2015

Insight into inner magnetic layers: Measurements at BESSY II have shown how spin filters forming within magnetic sandwiches influence tunnel magnetoresistance -- results that can help in designing spintronic component- February 17th, 2015

A new spin on spintronics: Michigan team tests radiation-resistant spintronic material, possibly enabling electronic devices that will work in harsh environments February 17th, 2015

Nanoscale Mirrored Cavities Amplify, Connect Quantum Memories: Advance could lead to quantum computing and the secure transfer of information over long-distance fiber optic networks January 28th, 2015

Quantum Computing

Next important step toward quantum computer: Scientists at the University of Bonn have succeeded in linking 2 different quantum systems March 30th, 2015

A first glimpse inside a macroscopic quantum state March 28th, 2015

Quantum compute this -- WSU mathematicians build code to take on toughest of cyber attacks: Revamped knapsack code offers online security for the future March 26th, 2015

Building shape inspires new material discovery March 24th, 2015

Announcements

Rutgers, NIST physicists report technology with potential for sub-micron optical switches March 31st, 2015

Prototype 'nanoneedles' generate new blood vessels in mice: Scientists have developed tiny 'nanoneedles' that have successfully prompted parts of the body to generate new blood vessels, in a trial in mice March 31st, 2015

Super sensitive measurement of magnetic fields March 31st, 2015

Nanomedicine pioneer Mauro Ferrari at ETH Zurich March 31st, 2015

Alliances/Partnerships/Distributorships

NXP and GLOBALFOUNDRIES Announce Production of 40nm Embedded Non-Volatile Memory Technology: Co-developed technology to leverage GLOBALFOUNDRIES 40nm process technology platform March 24th, 2015

Young NTU Singapore spin-off clinches S$4.3 million joint venture with Chinese commercial giant March 23rd, 2015

Halas, Nordlander awarded Optical Society's R.W. Wood Prize: Rice University researchers recognized for pioneering nanophotonics March 21st, 2015

EU Funded PCATDES Project has completed its half-period with success March 19th, 2015

Quantum nanoscience

Super sensitive measurement of magnetic fields March 31st, 2015

Using magnetic fields to understand high-temperature superconductivity: Los Alamos explores experimental path to potential 'next theory of superconductivity' March 27th, 2015

Thousands of atoms entangled with a single photon: Result could make atomic clocks more accurate March 26th, 2015

Bar-Ilan U. researchers identify 'tipping point' between quantum and classical worlds: Study sheds new light on 'spooky' quantum optics March 24th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE