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Open-Destination Quantum Teleportation
Roland Piquepaille writes "An international team of physicists has entangled five photons for the first time in the world, reports Technology Research News in "Five photons linked." Why is this important? Because it's the minimum number of qubits needed for universal error correction in quantum computing. In other words, they found a way to check computational errors in future quantum computers. The physicists also demonstrated what they call 'open-destination teleportation,' a way to teleport quantum information within and between computers." "They teleported the unknown quantum state of a single photon onto a superposition of three photons. They were then able to read out this teleported state at any one of the three photons by performing a measurement on the other two photons," adds PhysicsWeb in "Entanglement breaks new record
". This will be used in about ten to twenty years to move information among quantum networks. You'll find more details and references in this overview."
Blah Blah Blah Blah,Blah,Blah, You have the bridge #1.
oh man... please stop... I dread reading the replys to this story... so so many people not understanding will come up. its not faster than light communication... I promise...
-You're wasting your time. Alfador only likes me.
Yet another lazy article submitter copies the article verbatim and gives no credit.
Ok... so when do I get to stroll downstairs in the morning and say "Energize" to some guy standing at the controls of my transporter pad to get to work, rather than driving?
Professor: No fair! You changed the outcome by measuring it!
Open-Destination Teleportation...wasn't this already tested with success? Yea, I seem to remember a story about this. Something about all hell breaking lose and killing all the Marines/scientists that were working on the project though...
...I empathize with Barbie. Math is hard.
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Writers get in shape by pumping irony.
The physicists also demonstrated what they call 'open-destination teleportation,' a way to teleport quantum information within and between computers."
See honey, I wasn't lying when I told you I knew nothing about it!
One of those physicists must have teleported that donkey porn onto my computer!
Opinions on the Twiddler2 hand-held keyboard?
For those of us who failed High School physics, from Wikipedia: A qubit (quantum + bit; pronounced /kyoobit/ [1] ) is a unit of quantum information. That information is described by state in a 2-level quantum mechanical system.
To be perfectly honest, quantum computing scares me to some extent. Things like PGP encryption and other very sensitive operations could, quite literally overnight, be blown away and dangerously shift power quickly. Then again we will also usher in a new age of unlimited (well, from a 2004 perspective, matter itself ultimately has a limit for storage and processing) computing that can make engineering in all fields like nothing we have seen before. And, the best part, we will see it in our lifetimes.
In quantum teleportation, complete information about the quantum state of a particle is instantaneously transferred by the sender, who is usually called Alice, to a receiver called Bob.
So, this would only be useful for sending information about a quantum state to guys named Bob? The quantum state thing is limiting enough, but c'mon ... Bob?
Well, tell you what. I'm changing my name to Bob. If you can't beat them, join them. I mean, these guys will be the information uberlords of the future. People will queue up to them, asking 'Did anything come for me yet?' And they will go, like, 'Show me the money!'
The Bobs of the future will be ultra-popular and rich.
...
Yes, I haven't taken my medication today? Why do you ask? :P
I hear there's rumors on the Slashdots
"they found a way to check computational errors in future quantum computers."
Just how far in the future will we be able to check? Should be a great aid to debugging! But what happens if I fix a problem that causes my great grandson to come back in time to help me to meet my wife? Oh, wait.
Not in the quantum world. You can transport the data, but you cannot copy the data. This is one of the primary premises of Quantum Computation, covered by the No Cloning Theorem.
Ofcourse, if you are talking about the inherent parallelism in q.c., you are right.
What we don't know about quantum physics would float many battleships.
What we may be seeing is the physical evidence that space and time are not much at all like we think they are.
Entanglement seems to allow things far away from each other, that used to be close to each other, to react to each other like they are still close to each other.
Science fiction fans will understand that the most likely explanations for that kind of thing are also likely to be wrong.
I look forward to a better understanding of this kind of behavior because it will allow us to better manipulate and control the way our area of the universe works.
For those who think of this as star trek blek, try putting yourself in the place of someone 200 years ago who was told that someone who lives in England would be able to visit someone in the colonies by a trip of only 3 hours.
dzimmerm (who is at work and whose account does not seem to recognize his password and who does not have any way to pop his home email from work due to SPIT, filtering, and SPIT lotus notes)
In 1993 an international group of six scientists, including IBM Fellow Charles H. Bennett, confirmed the intuitions of the majority of science fiction writers by showing that perfect teleportation is indeed possible in principle, but only if the original is destroyed. In subsequent years, other scientists have demonstrated teleportation experimentally in a variety of systems, including single photons, coherent light fields, nuclear spins, and trapped ions. Teleportation promises to be quite useful as an information processing primitive, facilitating long range quantum communication (perhaps unltimately leading to a "quantum internet"), and making it much easier to build a working quantum computer. But science fiction fans will be disappointed to learn that no one expects to be able to teleport people or other macroscopic objects in the foreseeable future, for a variety of engineering reasons, even though it would not violate any fundamental law to do so.
In the past, the idea of teleportation was not taken very seriously by scientists, because it was thought to violate the uncertainty principle of quantum mechanics, which forbids any measuring or scanning process from extracting all the information in an atom or other object. According to the uncertainty principle, the more accurately an object is scanned, the more it is disturbed by the scanning process, until one reaches a point where the object's original state has been completely disrupted, still without having extracted enough information to make a perfect replica. This sounds like a solid argument against teleportation: if one cannot extract enough information from an object to make a perfect copy, it would seem that a perfect copy cannot be made. But the six scientists found a way to make an end run around this logic, using a celebrated and paradoxical feature of quantum mechanics known as the Einstein-Podolsky-Rosen effect.
Read just how this effect works, here.
You are missing something. This has got nothing to do with faster than light communication, instead it's on how they were able to successfully entangle 5 photons, which is the minimum number needed to implement a universal error correction system in quantum computation.
Teleportation was achieved a long time ago by a bunch of folks at Innsbruck, led by Prof Anton Zeilinger.
And you call yourselves nerds!
Thanks to quantum computation and teleportation, this is actually the first post.
rewriting history since 2109
As I understand it, the 'information' moves instantly (FTL), but the ability to read it doesn't, hence no faste-than-light violation.
"A language that doesn't affect the way you think about programming, is not worth knowing" - Alan Perlis
On my systems three Q*berts is not sufficient for error correction in my simulations. Coily always gets me sooner rather than later.
(Disclaimer: IAAQP)
Yes. They can transmit the data, but they cannot preserve the data without losing information. This is one of the primary ideas behind Quantum Cryptography, which forbids eavesdroppers from creating copies of the transmitted data.
I'm not talking about approximation -- I'm talking of copying the basic qubit as a function of quantum states -- no two quantum states can be copied, and if this were possible it would result in some funny stuff like causality.
You don't have to believe me, see for yourself - No Cloning Theorem.
In one hour? To quote from the article, "Quantum computers have the potential to be blazingly fast because a string of quantum bits, or qubits, that store the ones and zeros of computer information can represent all the numbers possible within that string at once."
In other words, in the time it takes you to transfer a single porn movie, you can simultaneously transmit _every_ porn movie of the same size or less.
Now that's a lot of porn.
Quantum teleportation is akin to faxing a document and in the process destroying the original.
[Scene: RIAA Headquarters]
Mitch Bainwol: "This quadrant teleportation thing sounds too good to be true."
Cary Sherman: "Get me Orrin Hatch on the phone. We need mandatory quantum teleplantation by 2010."
They didn't really know the dangers of nuclear power when they started messing with it. The first nuclear reactors were built right under campus stadiums. What if quantum computing messes with or pollutes something we don't know about yet? Maybe there is "probability pollution" or something.
:-)
Hell, it might be decreasing further the chances of nerds getting dates or something
Table-ized A.I.
So here's the idea - quantum entanglement is when you have two quantum states that have to be given in reference to each other, even though the two states maybe contained in elements spatially separated.
:)
But - no useful information can be transmitted between the two systems. This is because the information in itself is given by probabilistic superposition of the states. For instance, you have a Qubit defined as the superposition of states, given by |psi> = a|0> + b|1> - so you can only find out when they are absolute states (0) or (1), and not in between -- and that will not happen at speeds less than the speed of light. In order to find out what state the system is in (in between 0&1), you will need to be able to copy the state, which is prohibited by the No Cloning Theorem.
So, to answer your question - you *may* be able to achieve instantaneous transmission of information, but you can never observe that information in a causal fashion less than the speed of light. Did that make sense?
They get it working already. Only problem is when you are teleported you get a goatee and become evil.
I hate to be cynical, but who's funding this kind of research, directly or indirectly? Now think about this strategy:....
That's very true, but what I am talking about are the obvious patents, not the ones that require millions of dollars in legitimate investment in R&D. I'm talking about silly little patents that take someone a few hours of thinking and then they try to claim any use of quantum mechanics in some broad area of endeavor (like using qubits to optimize internet routings, or using entanglement to serve ads, or some such "add-a-q-to-any-ordinary-activity" type of patent).
Personally, I am in favor of patents for non-trivial inventions. I wonder if part of the problem with the current patent system is that the examiners may not understand the state of the art well enough to judge which inventions were obvious and which inventions were hard. The point is that easy inventions don't need the encouragement created by a patent -- they will get invented and deployed anyway. Patents should reserved for inventions that could not have happened if the inventor did not think they had a chance of a patent.
It's a separate issue, entirely, whether the fruits of publicly funded research should be patented at all, but that's a different discussion.
Two wrongs don't make a right, but three lefts do.
Very good article, but some people might find Einstein-Podolsky-Rosen paradox article on Wikipedia somewhat better for an introductory text, and at the same time richer in details:
The EPR paradox arises in a thought experiment which shows that quantum mechanics leads to very counter-intuitive and paradoxical consequences. It is named after Einstein, Podolsky, and Rosen, who published the idea in 1935. It is also referred to as the EPRB paradox after Bohm, who converted the idea into something that was nearer to being experimentally testable. The EPR paradox draws attention to a phenomenon predicted by quantum mechanics known as quantum entanglement, in which measurements on spatially separated quantum systems can instantaneously influence one another. As a result, quantum mechanics violates a principle formulated by Einstein, known as the principle of locality or local realism, which states that changes performed on one physical system should have no immediate effect on another spatially separated system. The principle of locality is persuasive, both in intuitive grounds and because it seems at first sight to be a natural outgrowth of the theory of special relativity. According to relativity, information can never be transmitted faster than the speed of light, or causality would be violated. Any theory which violates causality would be deeply unsatisfying, and probably internally inconsistent. However, a detailed analysis of the EPR scenario shows that quantum mechanics violates locality without violating causality, because no information can be transmitted using quantum entanglement. Nevertheless, the principle of locality appeals powerfully to physical intuition, and Einstein, Podolsky and Rosen were unwilling to abandon it. They suggested that quantum mechanics is not a complete theory, just an (admittedly successful) statistical approximation to some yet-undiscovered description of nature. Several such descriptions of quantum mechanics, known as "local hidden variable theories" were proposed. These deterministically assign definite values to all the physical quantities at all times, and explicitly preserve the principle of locality. Of the several objections to the prevailing interpretation of the quantum mechanics spearheaded by Einstein, the EPR paradox was the subtlest. It is at present considered to have been unsuccessful, the existence of hidden variables having been refuted experimentally and the EPR "paradox" taken to be fully resolved within the current interpretation of the theory. The belief that entanglement is a real phenomenon has led to a radical shift in thinking about 'what is reality' and what is a 'state of a physical system'. First, a review of the history: Before 1936, the generally accepted view was that a particle, such as an electron, has measurable properties such as a position and a momentum but 'we cannot know both' at the same time. This view is present in some explanations of the Heisenberg uncertainty principle. In such an explanation, the 'more exactly we measure the position', the 'more we disturb the particle' and its momentum becomes that much less certain. The numerical measure of uncertainty satisfies Heisenberg's principle, but this (local realistic) interpretation is rejected in professional circles, though it still lives in popular books. The shift was caused by the EPR thought experiment, which has shown how to measure the property of a particle, such as a position, without disturbing it. In to
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
This is how i read it too - but one thing doesn't make sense to me.
If the particles are entangled, and it observe one of the observer ones, isn't that going to change all of them because they are still entangled?
or do you unentangle them before you observe them? Can you unentangle particles without changing their state?
The probability "amplitude" that represents a solution to say, Satisfiability, would, on average, be 2^-N. To distinguish a possible solution probabilistically from 0, 2^N trials would be needed. Or so says "A New Kind of Science" by Wolfram.
That's right. All your base.
No, that's the whole point of quantume entanglement.
Entangled particles are created in a process that conserves quantume properties, like spin. So if a particle is in the spin up state, the other has to be in the spin down state. When they are created, entangled couples are in a undetermined state. As soon as a measurement is made on one of the particles, the other collapse to the complementary state. This happens instantaneously, regardelss of the distance between the particles. However, since you cannot predict the result of the measurements, you cannot transfer information with this method. You can however use it to create secure keys fro criptography.
I haven't seen this mentioned in the threads yet so...
Quantum computing will NOT necessarily speed up all your porn browsing, DOOM playing arses. Instead, Quantum computing affects a set of computational problems that fall into the category of "Non-Determinstic time" algorithms. Non-Determinstic algorithms are identifiable by the fact that they all benefit hugely from being run in parallel. Basically a good rule of thumb is that quantum computing will affect algorithms that gain from being run on massive numbers of processors simultaneously given different (but not inter-communicating) inputs.
Some such problems are:
--Most if not all current cryptography
--SETI
--Other problems where you're looking for one specific output given a potentially huge number of inputs.
As an example in cryptography, a sufficiently powerful quantum computer would be able to break your RSA, DSA, DES3 or any other symmetric or non-symmetric cypher instantaneously if the author of the quantum program knew what they were looking for.
I'm suprised no one has mentioned it so far in the threads...
Karma: The only way to win is not to play.
Werner Heisenberg was pulled over...
Get your Unix fortune now!
1.)
Austria != Australia
In Austria there are NO kangaroos, but the Alps, Mozart, Beethoven, Sissy, Schwarzenegger and the river danube in the middle of europe!
2.)
It should not be "Hans J. Briegal of the Australian Academy of Sciences"
but
"Hans J. Briegel of the Austrian Academy of Sciences"
Read more at the University of Innsbruck/Austria page:
http://homepage.uibk.ac.at/homepage/c705/c705114/