World Record for Entanglement of Twisted Light Quanta.
23 replies, posted
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[IMG]http://images.sciencedaily.com/2012/11/121102115344.jpg?1351883202[/IMG]
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A long-exposure photo of laser light in 'donut modes' (light beams with no intensity in the middle). (Credit: Robert Fickler, University of Vienna)
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The Vienna research team led by Anton Zeilinger has achieved a new milestone in the history of quantum physics: The scientists were able to generate and measure the entanglement of the largest quantum numbers to date.
To this end, the researchers developed a new method for entangling single photons which gyrate in opposite directions. This result is a first step towards entangling and twisting even macroscopic, spatially separated objects in two different directions. The researchers at the Vienna Center for Quantum Science and Technology (VCQ), situated at the University of Vienna, and the Institute for Quantum Optics and Quantum Information (IQOQI) at the Austrian Academy of Sciences have were able to get their pioneering results published in the current issue of the scientific journal Science.
Quantum physics is usually considered to be the theory of extremely lightweight objects, such as atoms or photons, or of exceptionally small units, namely very small quantum numbers. One of the most fascinating phenomena of quantum physics is that of entanglement. Entangled quanta of light behave as if able to influence each other -- even as they are spatially separated. The question of whether or not entanglement is limited to tiny objects or very small quantum numbers came up already in the early days of quantum physics. Now, the Vienna group has taken the first step for testing quantum mechanical entanglement with rotating photons. To illustrate, a quantum mechanical figure skater would have the uncanny ability to pirouette both clockwise and counter-clockwise simultaneously. Moreover, the direction of her rotations would be correlated with the twirls of another, entangled, skater -- even if the two ice dancers whirl far removed from each other, in ice rinks on different continents. The faster the two quantum skaters pirouette, the larger is the quantum number of their rotation direction, the so-called angular momentum. "In our experiment, we entangled the largest quantum numbers of any kind of particle ever measured," declares Zeilinger with a wry smile.
[B]Could quantum ice dancers exist in reality?[/B]
It has been common knowledge for about 20 years now that theoretically, there is no upper limit for the angular momentum of photons. Previous experiments, however, have been limited, due to physical restrictions, to very weak angular momentum and small quantum numbers. In the Vienna experiment, it is theoretically possible to create entanglement regardless of the strength of the angular momentum or the scale of its quantum number. "Only our limited technical means stop us from creating entanglement with twisted photons that could be sensed even with bare hands," states Robert Fickler, the main author of the current Science publication. And so, the researchers have demonstrated that it is possible in principle to twirl entangled ice skaters simultaneously both in clockwise and counter-clockwise directions. In practice, a number of major challenges need to be addressed before such an experiment can be realized with macroscopic objects.
[B]From fundamental research to technical applications.[/B]
In addition to the fundamental issue of the limits of macroscopic entanglement, the physicists address possibilities of potential applications. They are, for example, able to use the created photons for very precise angular measurements already at low intensities of light. This feature is of advantage in particular when investigating light sensitive materials, as for example some biological substances. "The special features of entanglement provide the fantastic possibility to perform such measurements from arbitrary distances and without any contact whatsoever with the measured object, or even at a point in time that lies in the future!" Fickler explains.
This research was supported by the European Research Council (ERC) and the Austrian Science Fund (FWF).
[B]Journal:[/B]
R. Fickler, R. Lapkiewicz, W. N. Plick, M. Krenn, C. Schaeff, S. Ramelow, A. Zeilinger. Quantum Entanglement of High Angular Momenta. Science, 2012; 338 (6107): 640 DOI: 10.1126/science.1227193
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Source:
[URL]http://www.sciencedaily.com/releases/2012/11/121102115344.htm[/URL]
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I just can never understand these articles.
Could someone sum it up for me, please? I get what entanglement is, but what's the breakthrough?
[QUOTE='[Green];38298417']I just can never understand these articles.
Could someone sum it up for me, please? I get what entanglement is, but what's the breakthrough?[/QUOTE]
2 entangled entities will always "reflect" each other (Change one, the other reacts, so on) and over any distance, instantly (space does not matter, the speed of light is "bypassed") And what they basically did, is make it a LOT easier to measure them (instead of teeny TINY particles, they used much larger ones).
Basically, we're getting closer to instant communication (Basically an Ansible).
[QUOTE=glitchvid;38298431]2 entangled entities will always "reflect" each other (Change one, the other reacts, so on) and over any distance, instantly (space does not matter, the speed of light is "bypassed") And what they basically did, is make it a LOT easier to measure them (instead of teeny TINY particles, they used much larger ones).
Basically, we're getting closer to instant communication (Basically an Ansible).[/QUOTE]
magic, got it...
[QUOTE=glitchvid;38298431]2 entangled entities will always "reflect" each other (Change one, the other reacts, so on) and over any distance, instantly (space does not matter, the speed of light is "bypassed") And what they basically did, is make it a LOT easier to measure them (instead of teeny TINY particles, they used much larger ones).
Basically, we're getting closer to instant communication (Basically an Ansible).[/QUOTE]
Well, not an ansible yet, only quantum information can be transmitted via entanglement, which is purely random. However, a medal to you for so consiely summing up entanglement.
PS. have a look at the delayed choice quantum eraser for potential ftl comms.
[QUOTE=glitchvid;38298431]2 entangled entities will always "reflect" each other (Change one, the other reacts, so on) and over any distance, instantly (space does not matter, the speed of light is "bypassed") And what they basically did, is make it a LOT easier to measure them (instead of teeny TINY particles, they used much larger ones).
Basically, we're getting closer to instant communication (Basically an Ansible).[/QUOTE]
Which, to put it in terms that interest most of this board, means no lag in online games (that is, when we reach instant information transfer, we aren't there yet this is just a step).
Also more important stuff like not having to wait several minutes for a message to reach Earth from an eventual colony on some other planet.
This is awesome.
[QUOTE=glitchvid;38298431]2 entangled entities will always "reflect" each other (Change one, the other reacts, so on) and over any distance, instantly (space does not matter, the speed of light is "bypassed") And what they basically did, is make it a LOT easier to measure them (instead of teeny TINY particles, they used much larger ones).
Basically, we're getting closer to instant communication (Basically an Ansible).[/QUOTE]
It's shown that quantum mechanics does not violate relativity. Instant communication my ass.
I can't remember who did it, but it was some Bell-laboratories experiment in the 70's that failed horribly.
[QUOTE=Number-41;38298919]It's proven that quantum mechanics does not violate relativity. Instant communication my ass.[/QUOTE]
Yep, to people who think that external information is transferred between the entangled particles, you would be incorrect. The only thing that is 'transferred' is the internal quantum state.
[QUOTE=Rct33;38299007]Yep, to people who think that external information is transferred between the entangled particles, you would be incorrect. The only thing that is 'transferred' is the internal quantum state.[/QUOTE]
Explain how this would negate instant communication please.
[QUOTE=qwerty000;38299050]Explain how this would negate instant communication please.[/QUOTE]
You can't put any information into it. How hard is it to understand.
[editline]3rd November 2012[/editline]
Like an envelope that's already sealed, you can't put a letter into it anymore.
[QUOTE=DrLuckyLuke;38299174]You can't put any information into it. How hard is it to understand.
[editline]3rd November 2012[/editline]
Like an envelope that's already sealed, you can't put a letter into it anymore.[/QUOTE]
Exceptionally difficult, it's utterly outside our day-to-day experiences and is completely counter-intuitive.
Building on your analogy of the envelopes;
We have two envelopes, and two coloured pieces of card, red and green. One card is put in each envelope, and two postmen take the envelopes to separate rooms.
When one postman opens the envelope and finds the red card, he knows, faster than light, that the other guy has the green card. However, he has no way of knowing which card he was going to end up with. The information is completely random, and hence useless for communication.
[QUOTE=QwertySecond;38299680]Exceptionally difficult, it's utterly outside our day-to-day experiences and is completely counter-intuitive.
Building on your analogy of the envelopes;
We have two envelopes, and two coloured pieces of card, red and green. One card is put in each envelope, and two postmen take the envelopes to separate rooms.
When one postman opens the envelope and finds the red card, he knows, faster than light, that the other guy has the green card. However, he has no way of knowing which card he was going to end up with. The information is completely random, and hence useless for communication.[/QUOTE]
But couldn't you, with that logic, develop a binary system where the card itself is useless, but opening the envelope equals a 1 and having it closed for, say, 1 second equals a 0? If each postman instantly knows when the other has opened the envelope that is.
The ability to change a state conveys information, however. It doesn't matter what is conveyed. The simplest of information can be communicated via binary representation. All we need is this ability in order to communicate successfully.
Can't you alter the spin or state of one entangled atoms and have the same thing replicated with the other entangled atom?
FTL communications are not possible. I'm not going to pretend I know anything about it so here's the wiki links to the laws/theorems that quantum FTL communication breaks.
[url]http://en.wikipedia.org/wiki/No_cloning_theorem[/url]
which leads to
[url]http://en.wikipedia.org/wiki/No-communication_theorem[/url]
[QUOTE=Swebonny;38299838]FTL communications are not possible. I'm not going to pretend I know anything about it so here's the wiki links to the laws/theorems that quantum FTL communication breaks.
[URL]http://en.wikipedia.org/wiki/No_cloning_theorem[/URL]
which leads to
[URL]http://en.wikipedia.org/wiki/No-communication_theorem[/URL][/QUOTE]
''The no-cloning theorem [B]does not prevent superluminal communication via quantum entanglement[/B], as cloning is a sufficient condition for such communication, but not a necessary one.''
''The no-communication theorem thus says shared entanglement alone can not be used to transmit any information. Compare this with the no teleportation theorem, which states a classical information channel can not transmit quantum information. (By transmit, we mean transmission with full fidelity.) [B]However, quantum teleportation schemes utilize both resources to achieve what is impossible for either alone[/B].''
These sentences seems to contradict you.
[QUOTE=Swebonny;38299838]FTL communications are not possible. I'm not going to pretend I know anything about it so here's the wiki links to the laws/theorems that quantum FTL communication breaks.
[url]http://en.wikipedia.org/wiki/No_cloning_theorem[/url]
which leads to
[url]http://en.wikipedia.org/wiki/No-communication_theorem[/url][/QUOTE]
This says "based on what we know it's impossible".
You can't say with absolute confidence it's impossible forever.
[editline]3rd November 2012[/editline]
Plus, above.
[QUOTE=Awesomecaek;38299975]This says "based on what we know it's impossible".
You can't say with absolute confidence it's impossible forever.
[editline]3rd November 2012[/editline]
Plus, above.[/QUOTE]
Yeah definitely, should have made it more clear.
[QUOTE=Mechanical43;38299955]''The no-cloning theorem [B]does not prevent superluminal communication via quantum entanglement[/B], as cloning is a sufficient condition for such communication, but not a necessary one.''
''The no-communication theorem thus says shared entanglement alone can not be used to transmit any information. Compare this with the no teleportation theorem, which states a classical information channel can not transmit quantum information. (By transmit, we mean transmission with full fidelity.) [B]However, quantum teleportation schemes utilize both resources to achieve what is impossible for either alone[/B].''
These sentences seems to contradict you.[/QUOTE]
Hm yeah you're right. The no-cloning theorem seems to state that you can't clone quantum states, which would make superluminal communication that's described in the EPR thought experiment invalid. But it seems it doesn't prevent other possible ways it may transfer information faster than light. So the no cloning theorem forbids superluminal communication just for the "cloning" method. That's a badly worded sentence.
and about the quantum teleportation thing, I think it's talking about quantum information and not classical, as stated in [URL]http://en.wikipedia.org/wiki/Quantum_teleportation:[/URL]
"Quantum teleportation, or entanglement-assisted teleportation, is a process by which a qubit (the basic unit of quantum information) can be transmitted exactly (in principle) from one location to another, without the qubit being transmitted through the intervening space. [B]It is useful for quantum information processing. However, it does not immediately transmit classical information, and therefore cannot be used for communication at superluminal (faster than light) speed.[/B]"
So, as Awesome said: "based on what we know it's impossible".
Edit: This guy : [URL]http://en.wikipedia.org/wiki/John_G._Cramer[/URL] is working on an experiment that tries another method than described earlier.
" He is currently engaged in experiments at the University of Washington to test [URL="http://en.wikipedia.org/wiki/Retrocausality"]retrocausality[/URL] by using a version of the [URL="http://en.wikipedia.org/wiki/Delayed_choice_quantum_eraser"]delayed choice quantum eraser[/URL] without [URL="http://en.wikipedia.org/wiki/Coincidence_counting"]coincidence counting[/URL]. [B]This experiment, if successful, would imply that entanglement can be used to send a signal [/B][I][B]instantaneously between two distant locations (or a message backwards in time from the apparatus to itself).[/B] Such "spooky communication" experiments have never been successfully conducted, and [B]only attempted a limited number of times, since most physicists believe that they would violate the [URL="http://en.wikipedia.org/wiki/No-communication_theorem"]no-communication theorem[/URL]. [/B]However, a small number of scientists (Cramer among them) believe that there is no physical law prohibiting such communication."[/I]
I can only hope instant communication is invented in my lifetime, should it turn out to be a possibility.
[QUOTE=Oicani Gonzales;38300245]okay that means i can play league of legends with no lag? awesome thanks[/QUOTE]
you'll finish the game even before you started it, don't know if you'd want that
For the raters:
[IMG]http://www.phys.vt.edu/~takeuchi/relativity/notes/ArrowApple.gif[/IMG]
For some people travelling at a positive speed relative to you, they would see the spell hit before you pressed q
Not really instant, the data transfer rates would be terrible unless you used liek 8 quantumly linked things that can, 4 for sending and 4 for receiving. It also adds to the question how would a sensor pick up the data? I don't think quantum links share charges
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