Science
Related: About this forumScientists Report Finding Reliable Way to Teleport Data
Scientists in the Netherlands have moved a step closer to overriding one of Albert Einsteins most famous objections to the implications of quantum mechanics, which he described as spooky action at a distance.
In a paper published on Thursday in the journal Science, physicists at the Kavli Institute of Nanoscience at the Delft University of Technology reported that they were able to reliably teleport information between two quantum bits separated by three meters, or about 10 feet.
Quantum teleportation is not the Star Trek-style movement of people or things; rather, it involves transferring so-called quantum information in this case what is known as the spin state of an electron from one place to another without moving the physical matter to which the information is attached.
Classical bits, the basic units of information in computing, can have only one of two values either 0 or 1. But quantum bits, or qubits, can simultaneously describe many values. They hold out both the possibility of a new generation of faster computing systems and the ability to create completely secure communication networks.
Moreover, the scientists are now closer to definitively proving Einstein wrong in his early disbelief in the notion of entanglement, in which particles separated by light-years can still appear to remain connected, with the state of one particle instantaneously affecting the state of another.
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http://www.nytimes.com/2014/05/30/science/scientists-report-finding-reliable-way-to-teleport-data.html?_r=0
Mnemosyne
(21,363 posts)Glad to see QP being taken more and more seriously.
bananas
(27,509 posts)Wheeler's delayed-choice quantum eraser effects could get interesting.
Mnemosyne
(21,363 posts)any mention of quantum physics. I was always surprised that Einstein was so resistant to it.
truedelphi
(32,324 posts)I promise you chocolate chip cookies if you ever get to my neighborhood in No Calif.
caraher
(6,278 posts)"Is this teleportation, or just remote state preparation?"
The idea of that sentence is that, if at any moment during the process of "teleportation" you performed measurements on the electrons in question, you will never find them anywhere "in between" their initial and final locations. You would be tempted to say that one electron is always in one trap and the other is always in another trap at a different location. (I'd be tempted to say that too, except that I think the habit of referring to entangled electrons as if they were actually different particles, rather than a "bi-electron," is problematic.)
Whats certainly true is that "both" electrons basically just sit there. But an act of measurement performed at one location has effects, "instantly," at the other location (if you insist on thinking of them as different particles). So the information "teleports" from one location to the other, without anything passing through the space in between.
truedelphi
(32,324 posts)If you should get to Northern Calif., let me know. Cookies will be fresh out of the oven.
A great many people know physics, but many cannot explain a thing about it.
bananas
(27,509 posts)"Whats curious about the Chinese announcement is that CHAMP deorbited in 2010. So a curious question is when the team did this work. Clearly, the team has been sitting on this result for some time."
China Reveals First Space-Based Quantum Communications Experiment
June 10, 2013
The Chinese Quantum Science Satellite will launch in 2016 and aim to make China the first space-faring nation with quantum communication capability
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However, this experiment raises something of a puzzle. The Chinese team say they used a German satellite called CHAMP for their experiment. This was launched in 2000 and its mission was to make a precise gravity map of the Earth by bouncing lasers off it.
Whats curious about the Chinese announcement is that CHAMP deorbited in 2010. So a curious question is when the team did this work. Clearly, the team has been sitting on this result for some time.
Why publish it now? The answer may be a small but significant detail revealed in the final paragraph of the paper. Here Jian-Wei and co announce that they plan to launch the first quantum science experiment into space. The spacecraft is called the Chinese Quantum Science Satellite and it is scheduled for launch in 2016.
A quick Google search shows that the official Chinese news agency, Xinhau, revealed in March that its scientists were planning a quantum information and technology space experiment. But the announcement did not give the name of the satellite and appears to have had little if any coverage in the west.
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bananas
(27,509 posts)Quantum communications system was used at Party Congress in Beijing
Revelation that secret communications system was used at the party congress last autumn shows high level of security concern in Beijing
Stephen Chen binglin.chen@scmp.com
PUBLISHED : Friday, 21 June, 2013
Beijing was so worried about cyberspies during last autumn's party congress that it turned to a secret, state-of-the-art telecommunications network to handle sensitive information.
Use of the next-generation quantum encryption technology at the once-in-a-decade leadership transition was revealed in a passing remark reported last week in People's Daily.
Chinese scientists are well aware of how vulnerable data can be when it is being transmitted, describing it as the weakest link in their security.
Revelations by whistle-blower Edward Snowden that the US is targeting "network backbones" - through which huge amounts of data are transmitted - confirmed their fears.
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Now all major countries are pouring resources into developing large-scale quantum networks. China came late into the game, but it is now the subject of a major national project.
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