News
August 2004
Teleportation Physics
Study Air Force Special Report (1,670 Kb pdf)(local
mirror)
by Eric W. Davis (Thanks Tomcat !)
Wed Jun 16, 2004 04:17 PM ET www.reuters.com
Scientists demonstrate teleportation with
atoms
By Patricia Reaney (Found by Vaiden :) )
January 30, 2003 New York Times
Light Particles Are Duplicated More Than
a Mile Away Along Fiber
By KENNETH CHANG
Scientists demonstrate
teleportation with atoms
Wed Jun 16, 2004 04:17 PM ET
By Patricia Reaney
LONDON (Reuters) - It is not quite the "beam me up Scotty" teleportation
of Star Trek, but teams of scientists said on Wednesday they had made properties
jump from one atom to another without using any physical link.
Physicists in the United States and Austria for the first time have teleported
"quantum states" between separate atoms.
The breakthrough may not yet make it possible for people to disappear and reappear
somewhere else, like actors in a science fiction television show. But it could
help lead to "quantum computing" technology that would make superfast
computers.
Quantum states include physical properties such as energy, motion and magnetic
field.
"We've done it for the first time with massive particles, with atoms,"
Rainer Blatt, of the University of Innsbruck in Austria, told Reuters in a telephone
interview.
Two years ago scientists at the Australian National University announced they
had teleported a laser beam of light from one spot to another in a split second.
Blatt and his colleagues and another team of scientists at the National Institute
of Standards and Technology (NIST) in Boulder, Colorado reported the first teleportation
of atoms in two reports in the science journal Nature.
The achievement marks a major advance in the field of quantum computers, which
could outperform classical computers and transmit information at the speed of
light.
The basic theory of quantum teleportation was outlined in 1993 by physicist
Charles Bennett and his colleagues.
Quantum computing requires manipulation of information contained in the quantum
states of the atoms.
"Using teleportation as we've reported could allow logic operations to
be performed much more quickly," physicist David Wineland, the leader of
the NIST team, explained in a statement.
The research involved quantum entanglement -- in which the quantum states of
two or more particles are linked without physical contact.
"There are quite a few implications...more on the scientific side,"
Blatt said. "We are far away from beamers, like beam me up Scotty,"
he added.
© Reuters 2004. All Rights Reserved.
--------------------------------------------------------------------------------
January 30, 2003 New York Times
Light Particles Are Duplicated More Than a Mile Away Along Fiber
By KENNETH CHANG
mploying a facet of quantum mechanics that Albert Einstein called "spooky action at a distance," scientists have taken particles of light, destroyed them and then resurrected copies more than a mile away.
Previous experiments in so-called quantum teleportation moved particles of light about a yard. The findings could aid the sending of unbreakable coded messages, which is limited to a few tens of miles.
The new experiment used longer wavelengths of light than earlier ones, letting the scientists copy the light through standard glass fiber found in fiber optic cables. "The central issue is to move to telecom fibers and telecom wavelengths and telecom technology," said Dr. Nicolas Gisin, a physics professor at the University of Geneva and the senior author of an article today in the journal Nature. "This then allows us to go the long distance."
The experiments are a primitive realization of the transporter in the "Star Trek" television series that beams people from starship to planet. In coming years, it may be possible to use teleportation to imprint the exact quantum configuration of one atom to another. But teleporting something from the everyday world like a person that contains more than a trillion trillion atoms is highly unlikely, if not impossible.
Even with the light particles, photons, about one in a thousand were received at the other side.
"You're not very sure to arrive," a researcher, Dr. Hugo Zbinden, said about human teleportation.
Still, the experiments show that scientists can overcome a seemingly insurmountable conceptual barrier, the Heisenberg uncertainty principle. The principle states that the location and velocity of a particle cannot both be precisely measured at the same time. That would seem to make it impossible to teleport anything, even single particles, because without knowing their exact specifications they cannot be copied somewhere else.
Devised in 1993 by scientists led by Dr. Charles H. Bennett of the I.B.M. Thomas J. Watson Research Center in Yorktown Heights, N.Y., quantum teleportation produces pairs of "entangled" light particles that can be thought of as a pair of encoding and decoding rings. A message is combined with the encoding light particle. That combination goes to the recipient, who uses the decoding photon to decipher the message. Because no one else has the decoding photon, no one else can decipher the message.
Other encoding techniques using quantum cryptography are simpler, and a more
immediate use for teleportation would be as a repeater. Photons almost all peter
out after traveling about 50 miles through optical fiber. Teleportation would
enable the creation of copies every 50 miles or so, letting the message be sent
across an unlimited distance.