Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Physicists establish "spooky" quantum communication

Abstract:
Physicists at the University of Michigan have coaxed two separate atoms to communicate with a sort of quantum intuition that Albert Einstein called "spooky."

Physicists establish "spooky" quantum communication

ANN ARBOR, MI | Posted on September 15th, 2007

In doing so, the researchers have made an advance toward super-fast quantum computing. The research could also be a building block for a quantum internet.

Scientists used light to establish what's called "entanglement" between two atoms, which were trapped a meter apart in separate enclosures (think of entangling like controlling the outcome of one coin flip with the outcome of a separate coin flip).

A paper on the findings appears in the Sept. 6 edition of the journal Nature.

"This linkage between remote atoms could be the fundamental piece of a radically new quantum computer architecture," said Professor Christopher Monroe, the principal investigator who did this research while at U-M, but is now at the University of Maryland. "Now that the technique has been demonstrated, it should be possible to scale it up to networks of many interconnected components that will eventually be necessary for quantum information processing."

David Moehring, the lead author of the paper who did this research as a U-M graduate student, says the most important feature of this experiment is the distance between the two atoms. Moehring graduated and now has a position at the Max-Planck-Institute for Quantum Optics in Germany.

"The separation of the qubits in our entangled state is the most important feature," Moehring said. "Localized entanglement has been performed in ion trap qubits in the past, but if one desires to build a scalable quantum computer network (or a quantum internet), the creation of entanglement schemes between remotely entangled qubit memories is necessary."

In this experiment, the researchers used two atoms to function as qubits, or quantum bits, storing a piece of information in their electron configuration. They then excited each atom, inducing electrons to fall into a lower energy state and emit one photon, or one particle of light, in the process.

The atoms, which were actually ions of the rare-earth element ytterbium, are capable of emitting two different types of photon of different wavelengths. The type of photon released by each atom indicates the particular state of the atom. Because of this, each photon was entangled with its atom.

By manipulating the photons emitted from each of the two atoms and guiding them to interact along a fiber optic thread, the researchers were able to detect the resulting photon clicks and entangle the atoms. Monroe says the fiber optic thread was necessary to establish entanglement of the atoms, but then the fiber could be severed and the two atoms would remain entangled, even if one were "(carefully) taken to Jupiter."

Each qubit's information is like a single bit of information in a conventional computer, which is represented as a 0 or a 1. Things get weird on the quantum scale, though, and a qubit can be either a 0, a 1, or both at the same time, Monroe says. Scientists call this phenomenon "superposition." Even weirder, scientists can't directly observe superposition, because the act of measuring the qubit affects it and forces it to become either a 0 or a 1.

Entangled particles can default to the same position once measured, for example always ending in 0,0 or 1,1.

"When entangled objects are measured, they always result in some sort of correlation, like always getting two coins to come up the same, even though they may be very far apart," Monroe said. "Einstein called this 'spooky action-at-a-distance,' and it was the basis for his nonbelief in quantum mechanics. But entanglement exists, and although very difficult to control, it is actually the basis for quantum computers."

Scientists could set the position of one qubit and know that its entangled mate will follow suit.

Entanglement provides extra wiring between quantum circuits, Monroe says. And it allows quantum computers to perform tasks impossible with conventional computers. Quantum computers could transmit provably secure encrypted data, for example. And they could factor numbers incredibly faster than today's machines, making most current encryption technology obsolete (most encryption today is based on the inability for man or machine to factor large numbers efficiently).

The paper is titled "Entanglement of single atom quantum bits at a distance."

####

About University of Michigan
Founded in 1817, the University of Michigan has stood as the national model for the large public university for more than a century. Recognized as one of the world's premiere research universities, U-M is a leader in undergraduate and graduate education, offering challenging academic programs.

More than 54,000 students on three U-M campuses ( Ann Arbor, Dearborn and Flint) come from every state and 129 countries. The Ann Arbor campus, with more than 39,000 students, offers 6,500 courses each year. Students can choose from more than 225 undergraduate majors and 600 degree programs offered by its 19 schools and colleges. Classes range in size from fewer than 10 to several hundred; the student/faculty ratio is 9:1.

For more information, please click here

Contacts:
Nicole Casal Moore
Phone: (734) 747-1838

Copyright © University of Michigan

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

Quantum Computing

1980s aircraft helps quantum technology take flight October 20th, 2014

Australian teams set new records for silicon quantum computing October 12th, 2014

Ultrafast remote switching of light emission October 2nd, 2014

Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014

Announcements

‘Designer’ nanodevice could improve treatment options for cancer sufferers October 22nd, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

Detecting Cancer Earlier is Goal of Rutgers-Developed Medical Imaging Technology: Rare earth nanocrystals and infrared light can reveal small cancerous tumors and cardiovascular lesions October 21st, 2014

Quantum nanoscience

NIST quantum probe enhances electric field measurements October 8th, 2014

Quantum environmentalism: Putting a qubit's surroundings to good use October 2nd, 2014

Rice launches Center for Quantum Materials: RCQM will immerse global visitors in cross-disciplinary research September 30th, 2014

Big Results Require Big Ambitions: Three young UCSB faculty receive CAREER awards from the National Science Foundation September 18th, 2014

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 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE