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In recent years, the Austrian physicist Anton Zeilinger has bounced entangled photons off orbiting satellites and made 60-atom fullerene molecules exist in quantum superposition--essentially, as a smear of all their possible positions and energy states across local space-time. Now he hopes to try the same stunt with bacteria hundreds of times larger.

Meanwhile, Hans Mooij of the Delft University of Technology, with Seth Lloyd, who directs MIT's Center for Extreme Quantum Information Theory, has created quantum states (which occur when particles or systems of particles are superpositioned) on scales far above the quantum level by constructing a superconducting loop, visible to the human eye, that carries a supercurrent whose electrons run simultaneously clockwise and counterclockwise, thereby serving as a quantum computing circuit.

But before technologies like quantum communications, computing, and metrology can realize their potential--a quantum Internet and uncounterfeitable money are two interesting possibilities--quantum networks must be able to transmit and store data. The quantum optics group at the California Institute of Technology has been working toward this goal.

Source: http://www.technologyreview.com/computing/23198/?a=f

Usually when physicists talk about quantum teleportation, they're referring to the transfer of quantum states from one particle to another without a physical link. Now, physicists have investigated a slightly different form of teleportation, in which they teleport a quantum field, or an entire beam of light, from one location to another. This kind of "strong" teleportation is required for some quantum information applications, and could lead to the teleportation of quantum images.

They have proposed a scheme for teleporting a beam of light, including its fluctuations over time. They hope to show that it’s possible that a physical object (e.g. a quantum field) in one location could emerge at another location in the same quantum state, so that any conceivable measurement would yield the same result in both locations. In contrast, previous teleportation schemes do not seriously consider reproducing certain elements, such as temporal fluctuations.

Source: http://www.physorg.com/news166779852.html

Scientists at the California Institute of Technology (Caltech) have developed an efficient method to detect entanglement shared among multiple parts of an optical system. They show how entanglement, in the form of beams of light simultaneously propagating along four distinct paths, can be detected with a surprisingly small number of measurements. Entanglement is an essential resource in quantum information science, which is the study of advanced computation and communication based on the laws of quantum mechanics.

In the May 8 issue of the journal Science, H. Jeff Kimble, the William L. Valentine Professor and professor of physics at Caltech, and his colleagues demonstrate for the first time that quantum uncertainty relations can be used to identify entangled states of light that are only available in the realm of quantum mechanics. Their approach builds on the famous Heisenberg uncertainty principle, which places a limit on the precision with which the momentum and position of a particle can be known simultaneously.

Entanglement, which lies at the heart of quantum physics, is a state in which the parts of a composite system are more strongly correlated than is possible for any classical counterparts, regardless of the distances separating them.

Source: http://www.eurekalert.org/pub_releases/2009-05/ciot-cpd050809.php

In recent years, physicists have devised numerous ways to use the oddities of quantum mechanics to transmit and process information.

Now a team of researchers has announced an important step toward using this quantum information: the ghostly transfer of the quantum state of a single ion to another one a meter away. Since ions can store a quantum state for many seconds, this scheme for "quantum teleportation" could buy enough time for manipulations that allow long-distance communications that are immune to eavesdropping, or for computations that exploit the quantum mechanics to perform blazing fast calculations.

Source: http://www.technologyreview.com/computing/22013/?a=f

Physicists have taken a significant step toward creation of quantum networks by establishing a new record for the length of time that quantum information can be stored in and retrieved from an ensemble of very cold atoms. Though the information remains usable for just milliseconds, even that short lifetime should be enough to allow transmission of data from one quantum repeater to another on an optical network.

The new record – 7 milliseconds for rubidium atoms stored in a dipole optical trap – is scheduled to reported December 7 in the online version of the journal Nature Physics by researchers at the Georgia Institute of Technology. The previous record for storage time was 32 microseconds, a difference of more than two orders of magnitude.

"This is a really significant step for us, because conceptually it allows long memory times necessary for long-distance quantum networking," said Alex Kuzmich, associate professor in the Georgia Tech School of Physics and a co-author of the paper.

Source: http://www.physorg.com/news147881784.html