NOT SO SMALL: One of the diamond wafers used in the entanglement experiment, with a coin for scale.
Image: CQT
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Diamonds have long been available in pairs—say, mounted in a nice set of earrings. But physicists have now taken that pairing to a new level, linking two diamonds on the quantum level.
A group of researchers report in the December 2 issue of Science that they managed to entangle the quantum states of two diamonds separated by 15 centimeters. Quantum entanglement is a phenomenon by which two or more objects share an unseen link bridging the space between them—a hypothetical pair of entangled dice, for instance, would always land on matching numbers, even if they were rolled in different places simultaneously.
But that link is fragile, and it can be disrupted by any number of outside influences. For that reason entanglement experiments on physical systems usually take place in highly controlled laboratory setups—entangling, say, a pair of isolated atoms cooled to nearly absolute zero.
In the new study, researchers from the University of Oxford, the National Research Council of Canada and the National University of Singapore (NUS) showed that entanglement can also be achieved in macroscopic objects at room temperature. "What we have done is demonstrate that it's possible with more standard, everyday objects—if diamond can be considered an everyday object," says study co-author Ian Walmsley, an experimental physicist at Oxford. "It's possible to put them into these quantum states that you often associate with these engineered objects, if you like—these closely managed objects."
To entangle relatively large objects, Walmsley and his colleagues harnessed a collective property of diamonds: the vibrational state of their crystal lattices. By targeting a diamond with an optical pulse, the researchers can induce a vibration in the diamond, creating an excitation called a phonon—a quantum of vibrational energy. Researchers can tell when a diamond contains a phonon by checking the light of the pulse as it exits. Because the pulse has deposited a tiny bit of its energy in the crystal, one of the outbound photons is of lower energy, and hence longer wavelength, than the photons of the incoming pulse.
Walmsley and his colleagues set up an experiment that would attempt to entangle two different diamonds using phonons. They used two squares of synthetically produced diamond, each three millimeters across. A laser pulse, bisected by a beam splitter, passes through the diamonds; any photons that scatter off of the diamond to generate a phonon are funneled into a photon detector. One such photon reaching the detector signals the presence of a phonon in the diamonds.
But because of the experimental design, there is no way of knowing which diamond is vibrating. "We know that somewhere in that apparatus, there is one phonon," Walmsley says. "But we cannot tell, even in principle, whether that came from the left-hand diamond or the right-hand diamond." In quantum-mechanical terms, in fact, the phonon is not confined to either diamond. Instead the two diamonds enter an entangled state in which they share one phonon between them.
To verify the presence of entanglement, the researchers carried out a test to check that the diamonds were not acting independently. In the absence of entanglement, after all, half the laser pulses could set the left-hand diamond vibrating and the other half could act on the right-hand diamond, with no quantum correlation between the two objects. If that were the case, then the phonon would be fully confined to one diamond.
If, on the other hand, the phonon were indeed shared by the two entangled diamonds, then any detectable effect of the phonon could bear the imprint of both objects. So the researchers fired a second optical pulse into the diamonds, with the intent of de-exciting the vibration and producing a signal photon that indicates that the phonon has been removed from the system. The phonon's vibrational energy gives the optical pulse a boost, producing a photon with higher energy, or shorter wavelength, than the incoming photons and eliminating the phonon in the process.
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59 Comments
Add CommentAs I understand, quantum entanglement is necessarily not distance limited. As stated in the wikipedia entry:
Reply | Report Abuse | Link to this"Thus, there is a correlation between the results of measurements performed on entangled pairs, and this correlation is observed even though the entangled pair may have been separated by arbitrarily large distances."
IMO, the restricted separation distance of these diamonds allows that some physical signal of sufficient amplitude may be required to communicate or resonate the phonon, synchronizing the diamonds' states.
The subject is scientific and demands certain level of knowledge to both write or read it. I think the author didn't match the challenge this time. Or maybe he/she just had a deadline to meet.
Reply | Report Abuse | Link to thisWe should be writing articles so that people with less knowledge gain some of it, not lose every interest in the subject.
If you want to learn more about this marvelous phenomenon, I recommend "Entanglement" by Amir Aczel. Well written, aimed at the layman.
Reply | Report Abuse | Link to thisThe quantum entanglement of macroscopic objects may well turn out to have a practical application as an anti-theft, anti-tampering device. I may be wrong, but I remember reading somewhere that once the entanglement is broken there is no way to re-establish it exactly as it was before.
Reply | Report Abuse | Link to thisI'm sure they have taken that into account. They're not that clueless.
Reply | Report Abuse | Link to thisI'm sure they have taken that into account. They're not that clueless.
Reply | Report Abuse | Link to thisIt is interesting but can it not also be explained by 'regular' small-scale entanglement? For instance, two photons from the laser that is split are entangled, and they seem to pass this entanglement onto some particle in each diamond? Basically, I need a definition of 'macro-scale entanglement'.
Reply | Report Abuse | Link to this"We can't be 100 percent certain that they're entangled, but our statistical analysis shows that we're 98 percent confident in that, and we think that's a pretty good outcome"
Reply | Report Abuse | Link to thisNo, it's not. Until we know more about that remaining 2%, this is nothing more than conjecture.
What mechanism requires that the diamond wafers are separated by 15 only centimeters? Since the restriction is specifically stated it can only be assumed that at greater distances the two wafers cannot be induced to share the vibrational state imparted by a single photon.
Reply | Report Abuse | Link to thisI suggest that this limitation indicates that a vibrational inducing photon must be physically passing between the two wafers and that their vibrational states are not entangled quantum states.
If this is not the case, what explains the distance restriction?
Rather than a spooky action at a distance, this seems to represent a not-so-spooky action between macro objects at close proximity.
Hi JD, been awhile since we talked. The reason distance plays a factor is that it is very hard to keep the photons from interacting with something else, thus causing the "wave function to collapse", to use the older terminology. We all know light does not travel in straight lines but rather takes many paths, and the greater the distance, the greater the likelihood of decoherence. By the way, just as an aside, do you have a dislike of quantum theory? Sometimes that is the feeling I get. Just curious.
Reply | Report Abuse | Link to thisI imagine a future communication device using entangled items, instantaneous, unblockable, and not able to be listened in on. I only wonder how long will it take?
Reply | Report Abuse | Link to thisThe photons are produced by a coherent laser, so the explanation regarding an incoherent light source does not apply. Please consider the experimental conditions carefully.
Reply | Report Abuse | Link to thisAs described in this article, the experiment "used two squares of synthetically produced diamond [separated by 15 centimeters], each three millimeters across. A laser pulse [of coherent light], bisected by a beam splitter, passes through [each of] the diamonds; any photons that scatter off of the diamond to generate a phonon are funneled into a photon detector. One such photon [a deflected photon that has deposited some of its energy to produce a phonon resonance, losing some of its energy by extending it wavelength] reaching the detector signals the presence of a phonon in the diamonds."
The results of this experiment are not consistent with quantum entanglement, which specifies that synchronous quantum states are maintained among entangled entities (particles or even molecular buckyballs) at arbitrarily large distances without exchanging any EM signal between them.
It would seem that the diamond wafers that are claimed to be entangled by these researchers could be separated by great distances if no EM signal was being exchanged among the diamond wafers. Since they cannot be distantly separated I strongly suggest that their vibrational states are not entangled but are coordinated by a communicating phonon producing photon.
Mr. Matson, you are wrong. Quantum mechanics does not apply to macro objects. It isn't the diamonds that are in a state of superposition, simultaneously here and there. It's the photon and the phonon. Both are quantums of energy.
Reply | Report Abuse | Link to thisIn Schrodinger's thought experiment, it was the cat that's in superposition, simultaneously dead or alive. To replicate that phenomenon, the diamond must be simultaneously in a box and outside of it. But the location of the diamond was never in question in the real experiment.
The experiment is not really remarkable. It's the same as the double slit experiment. It's the photon that's in a quantum state not the slits.
I generally agree, except that it is K. C. Lee and the other authors of "Entangling Macroscopic Diamonds at Room Temperature" who mistakenly attempt to transfer quantum states of photons to the macroscopic diamond wafers. Again, in this experiment I suspect it is the dispersion of deflected photons that coordinates the resonance state of the two proximal diamond wafers. Unfortunately the research report is not freely available for detailed review.
Reply | Report Abuse | Link to thisI also must point out that phonon resonance of diamond lattices is not a fundamental characteristic property of diamonds. Unlike fundamental particle states such as their inherent propagation location or momentum, spin or polarization, diamond lattice resonation is an imposed condition imparted by the application of external energy. It is this externally imparted state condition that is responsible for the tenuous nature of the physically coordinated linked or supposedly 'entangled' states.
Reply | Report Abuse | Link to thisHere is the problem as I see it. A phonon is a virtual particle of sound. As such it has a wave length, and moves at the speed of sound in the medium. If I assume a wavelength large enough to occupy more than a macroscopic section of each diamond, then the period of the phonon is much larger than how long they claimed the entanglement lasted. So either they used a microscopic wavelength, and thus cannot prove macroscopic entanglement, or there is experiment is such that they cannot even prove the phonon existed at all.
Reply | Report Abuse | Link to thisBased on the timing of their measurements, the phonons must have had a microscopic wavelength. Hence they cannot prove if they had macroscopic entanglement on the whole crystals, or microscopic entanglement of sections on both crystals.
Reply | Report Abuse | Link to thisAs I understand, the phonon wavelength can be as small as the separation distance between the atoms comprising the crystal lattice structure. The vibrational phonon waves should propagate through the breadth of the diamond wafer. I suggest that it can then be reemitted as a photon, propagate to the second proximal diamond wafer, manifesting as a new phonon wave. The seven picoseconds may be the phonon propagation speed through diamond wafers with these specific dimensions. Please see:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/Phononic_crystal#Mechanics_of_lattice_waves
I dislike the probabilities of quantum theory, and want to have an explanation.
Reply | Report Abuse | Link to thisFor example, the entaglement can be the spacelike orinted waves of the special relativity, and the probability of a particle is the result of its entanglement with a lot of other patricles - the observer does not know of which ones.
a single photon carrying the results of both?
Reply | Report Abuse | Link to thisand, there is no return for any.
No, it's not sound. It's not an acoustic phonon. They are experimenting with optical phonons and light photons with energy of 1.6 to 3.4 electronvolts. The equivalent mass of 3.4 electronvolts is one-billionth the mass of a hydrogen atom. Definitely microscopic and subatomic.
Reply | Report Abuse | Link to thisCorrection: The equivalent mass of 3.4 electronvolts is one-thousandth the mass of a hydrogen atom. Still, definitely microscopic and subatomic.
Reply | Report Abuse | Link to thisUsing photons to make measurements is good but has nothing to do with how entanglement occurs over
Reply | Report Abuse | Link to thisgreat distances.
I don't believe there is such a thing as a particle of sound, let alone a virtual one. Sound is nothing more than waves of air compression travelling at the speed of sound through some medium, I don't know that their is anything particulate about it. It never acts as an individual particle, always as a wave travelling through a physical medium.;
Reply | Report Abuse | Link to this15 cm is a huge distance in terms of quantum effect. And confidence could easily be improved by running the experiment longer.
Reply | Report Abuse | Link to thisThe article doesn't explain this well but I presume that if the phonon was not entangled, the difraction pattern would be consistant with photons with different wavelengths merging on the two paths, which would be different from when entanglement does occur with identical wavelengths merging along both paths.
If the energy added is indeed one phonon, which is an indivisable amount of energy and this energy gets added to both crystals, hasn't one violated conservation of energy laws.
Photons and subatomic particles separated by large distances can be entangled. This does not prove large objects can be entangled.
Reply | Report Abuse | Link to thisIn the double slit real experiment, it is not the distance between the slits that matters. It is the fact that only subatomic particles exhibit this strange property. If you replace the photon or electron beam with a particle of dust composed of billions of atoms, you will not observe entanglement of dust particles. More so if you throw a cat to the slits, for sure the cat will pass just one of the slits but not both slits simultaneously. (unless you cut the poor cat in half)
The conservation of energy is not violated. In the summation of probabilities, the total energy equals one photon. The Uncertainty principle prevents you from accurately measuring both energy and time simultaneously. So in principle you can't measure the "violation."
1. The separation distance restriction violates a tenant of entanglement. As I mentioned in comment #1, http://en.wikipedia.org/wiki/Quantum_entanglement states:
Reply | Report Abuse | Link to this"Thus, there is a correlation between the results of measurements performed on entangled pairs, and this correlation is observed even though the entangled pair may have been separated by arbitrarily large distances."
2. I'm afraid your intermixing two separate experiments in quantum physics: quantum entanglement and the double-slit experiment. Please see the entanglement entry above, which does not involve the production of diffraction patterns whatsoever, and http://en.wikipedia.org/wiki/Double-slit_experiment
3. There is no "energy added". As the article states:
"Researchers can tell when a diamond contains a phonon by checking the light of the pulse as it exits. Because the pulse has deposited a tiny bit of its energy in the crystal, one of the outbound photons is of lower energy, and hence longer wavelength, than the photons of the incoming pulse."
A lot of physics is like this. This is the way all the results from big particle accelerator experiments are reported, for example.
Reply | Report Abuse | Link to thisIn a broader sense, it's NEVER possible to be 100% certain of any scientific conclusion. That's the nature of scientific knowledge. Theories can be falsified, but no matter how many times a theory passes a test, one cannot be 100% certain that another test might falsify it.
I can hear Richard Feynman now: "this is the way nature is. It doesn't matter whether you like it or not, that's the way it is. Nobody knows why it is like this, but that's the way it is".
Reply | Report Abuse | Link to thisOk, I had some cinfusion about what a phonon is within a diamond. Apparently it sets up a wave that vibrates throughout the entire diamond at the atomic level, yes? So, can someone please clarify/answer:
Reply | Report Abuse | Link to this1) Does a phonon ever exit a diamond? Basically, does the diamond eventually stop vibrating and shed the eccess energy?
2) This brings up a question I always had with Schrödinger's cat. The particle inside the box should affect the box. Maybe we can measure its affect on the box without affecting its state? When it is just a subatomic particle, seems doubtful. But in this 'macro-entanglement', the diamond is the box (or so it seems). It seems we should be able to measure how the diamond is affecting the world outside the diamond, thus know whether or not it contains a phonon.
3) could a phonon develop inside each diamond before the detector measures a photon with low energy? It seems it should be possible so I am not sure how the diamonds can ever be considered entangled. Or maybe they sometiems are entangled but you can never know if they actually are entangled? heh
It seems I am Penny in a comment thread full of Dr. Sheldon Coopers.
Reply | Report Abuse | Link to thishttp://fakebadtaste.files.wordpress.com/2010/11/internet-serious-business-cat.jpg
Regarding your point 1), the phonon, a vibrational wave propagating through the diamond's crystal lattice, I also speculated in my comment #18 that perhaps it would reach the periphery of the lattice and be reemited as a photon that might be propagated to the second diamond wafer, thus producing a phonon in each diamond with only a single photon. This would not infer any quantum entanglement, of course. Please see:
Reply | Report Abuse | Link to thishttp://en.wikipedia.org/wiki/Phononic_crystal#Mechanics_of_lattice_waves
At any rate, the 15 centimeter separation distance specification seems to infer that some EM signal of sufficient amplitude is communicated between the diamond wafers to coordinate phonon states among them.
Again, crucially, the specified separation distance restriction seems to violate the conditions for quantum entanglement, in which characteristic quantum state information is coordinated among particles separated by unrestricted, arbitrary distances.
The double slits experiment demonstrates quantum superposition. The "virtual" particles (actually just one particle) passing through the two slits are entangled. Entanglement is a form of quantum superposition. The two diamonds experiment demonstrates entanglement of the phonons in the two diamonds. Note that it is the phonons that are entangled not the whole diamond.
Reply | Report Abuse | Link to thisSorry, but I can't agree at all. To address only the most relevant statement, the article itself states:
Reply | Report Abuse | Link to this"To entangle relatively large objects, Walmsley and his colleagues harnessed a collective property of diamonds: the vibrational state of their crystal lattices."
It goes on:
"In quantum-mechanical terms, in fact, the phonon is not confined to either diamond. Instead the two diamonds enter an entangled state in which they share one phonon between them."
Note that these researchers claim that it is the two diamonds' vibrational states that are entangled.
As I understand, the double-slit experiment establishes the principle known as wave–particle duality.
I don't find support for your statements in any source.
Please provide some references supporting your assertions, especially explaining how a single photon might possibly be entangled!
Read the wikipedia entries on quantum superposition, quantum entanglement and double slit experiment. Sorry I will not respond to you anymore. I find many of your posts on physics wrong. It's annoying responding to somebody claiming falsehood to be true. Perhaps it's unintentional and a misunderstanding.
Reply | Report Abuse | Link to thisEntanglement is instant "communication".
Reply | Report Abuse | Link to thisIt conflicts with Einsteins relativity theory.
What if the speed of light isn't constant, as some physicists suggested recently?
What if the speed of light varies through time and space?
That would create some interesting theory. At least I think so.
Antimatter is the mind and consciousness of all living entities.
You are your own universe.
Reality is where the minds (antimatter) meets the physical universe.
Interested? Then read my philosophical multiverse theory.
Google crestroyer theory, and find it instantly.
http://crestroyertheory.com/the-theory/
Entanglement is instant "communication".
Reply | Report Abuse | Link to thisIt conflicts with Einsteins relativity theory.
What if the speed of light isn't constant, as some physicists suggested recently?
What if the speed of light varies through time and space?
That would create some interesting theory. At least I think so.
Antimatter is the mind and consciousness of all living entities.
You are your own universe.
Reality is where the minds (antimatter) meets the physical universe.
Interested? Then read my philosophical multiverse theory.
Google crestroyer theory, and find it instantly.
http://crestroyertheory.com/the-theory/
That's why it is called an experiment.
Reply | Report Abuse | Link to thisThis is evidence of a phenomenon, which requires measurment. Distance limitations in measurement limit distance in this early phase.
All of the above questions are answered in the article, either directly or in the 2% quote.
Fine - can you direct me to the explanation of the necessity for the 15 centimeter separation distance requirement? I don't have access to the $15 single article and am not a AAAS member/subscriber.
Reply | Report Abuse | Link to thisWell, just bringing up the double slit experiment doesn't seem to answer any of my 3 questions (I beleive I understand the comparison but my questions are more about measuring states in macro scale objects). I am no expert but I find entanglement of a particle to be rather different than entanglement of an entire occilating wavefront through a crystaline structure. A phonon is not a particle, it seems to be a definition of a state of 'excitation' in an object. Such states are usually measurable with methods that do not affect their state, which would place them outside of a indeterminate state (typically, these objects radiate something that you can measure to determine what state they are in). Now, I imagine that this might not be the case, the authors know what they are doing and this is pretty obvious. Mostly just wondering on this, as well as other points.
Reply | Report Abuse | Link to thisAnd JT's point does make sense to me. It may not be correct but there definitely seems to be some interesting questions to consider when you have two macro scale objects 'entangled' than two subatomic of particles.
This is in regard to the recent article "Entangled Macroscopic Diamonds at Room Temperature" and the accompanying editorial Science. I would like to make two points on this issue. 1. The use of the term 'entanglement' seems to be unsubstantiated. The phonons represent a mixed thermal state capableof generating quantum correlations in the photon pairs. In the setting of indistinguishable paths that fall within the detection window, thermal correlations will demonstrate nonlocal properties indistinguishable on measurement in this experimental set-up from those of entangled photons. If we examine just the second order coherence function as an example point, comparing entangled, thermal, and separable states we(1): EQUATIONS WON’T PASTE For coherent photons, the second order correlation function is separable. For entangled photons, the two are exactly correlated irrespective of the detection window (they can be measured at substantially different times with the same results). For thermal bi-photons, in the setting ofcompletely indistinguishable paths within the detection window, 50% of the bosons demonstrate quantum correlations(2). The paper jumps between the terms entangled and correlated as synonymous by their distinction, that they are not separable states. But thermal states, as in the last term in the last equation, can generate quantum correlations indistinguishable from entangled states under the experimental conditions. So while the discussion uses the term entanglement, the only evidence presented to distinguish it from quantum correlations, as the author’s admit, is figure 3. ( .. can only be inferred from the density matrix in Fig. 3). In figure 3, they defend the use of the term entanglement by “ .. is zero for any separable state and positive for all entangled states.” This ignores the possibilities of thermal correlations, which are likely what is being measured in the experiment. 2. In a paper in Physical Review published by our group in 2008, we established quantum correlations between two macroscopic mirrors under ambient conditions using a thermal source (3). This was not mentioned either the editorial or the paper. 1. This is from Shin, Y. An Introduction to Quantum Optics:. CRC Press 2011. 2. Chen, H., et. al., 2011. Observations of anti- correlations in incoherent thermal light fields. Phys. Rev. A. 84: 033835. 3. M. E. Brezinski, et. al., “Nonlocal Quantum Macroscopic Superposition in High-thermal low-purity state,” Physical Review A, 78, 063824 (2008).
Reply | Report Abuse | Link to thisAs a lay person, you have the advantage of superior knowledge plus simple access to the research report in Science.
Reply | Report Abuse | Link to thisHowever, this news article states:
"In quantum-mechanical terms, in fact, the phonon is not confined to either diamond. Instead the two diamonds enter an entangled state in which they share one phonon between them."
Concluding from this that it is both diamond wafers' vibrational state that is claimed to be entangled, the restricted 15 centimeters separation distance seems to be a violation of entanglement, as this does not preclude the physical communication of EM (thermal) signals coordinating the vibrational state of both diamond wafers.
Please let me know if this view is not consistent with your understanding of the actual experiment presumedly described in detail by the research report. Thanks.
I agree. I'd have liked to have seen a diagram showing the process. I was fine with the beam splitter prior to the diamonds, but wasn't able to visualise the photon collection and how it was impossible to establish the origin.
Reply | Report Abuse | Link to thisIt could have been a much better article. Although a layperson, I understand the principles of entanglement and am interested in it.
I recently bought 2 pizza from the Heisenberg Pizzaria. One black olive, the other mushroom. The boxes were unlabeled, so I had no idea which was which. In fact, they were each both. When I opened the first box, and found mushroom, entanglement collapsed the wave function of the second, turning it into black olive!
Reply | Report Abuse | Link to thisThat's the way it usually works, but in this experiment, every time someone screams 'You got the wrong pizza!', both pizzas alternatively turn into mushroom or black olive... It is very strange - perhaps if they'd separate the two pizzas & scream at only one they'd get them both right!
Reply | Report Abuse | Link to thisJust imagine what this could mean, travel, communication and even data transfer.
Reply | Report Abuse | Link to thishttp://voices.yahoo.com/what-does-quantum-entanglement-mean-future-10618637.html?cat=15
I wouldn't suggest holding you breath until your dreams come true!
Reply | Report Abuse | Link to thisGolden Shoes & Diamond's Too
Reply | Report Abuse | Link to thisby: Gerard Haughey
Golden Shoes & Diamond's Too
Reply | Report Abuse | Link to thisBy: Gerard Haughey
I lost my way, far away from home.
My shoes I made from the gold I never owned.
Still I walked like the righteous man, alone?
All alone in shoes with no soles.
The bottoms of my feet just blood and bone.
---
And where have I gone?
To some carnival of shame,
where fires burn away every letter of your name.
I look back and all I can see are golden footprints
upon the ruination of every thing that ever spoke of me.
--
My diamonds in hand, within a pill bottle they rattle.
Marching away towards nothing that matters.
I shine and I glitter,
all the way to Hell,
where my end will be bitter,
under this spell.
Entangled light ('entities') and thermal quantum correlations (quantum concordance is closely related) can produce almost the same results under many conditions. The authors say in the abstract there is 98% concordance (measure of entanglement) but then say in the discussion concordance is significant because of noise.... They say the only proof of entanglement is figure 3, which needs more information to validate. Thermal correlations can 'connect' two diamonds if the paths are indistinguishable, just like entangled photons, so the results are important. This is far more likely with thermal phonons over so many atoms. A difference is entangled photons are one entity (single wavepacket) so that measurement on one exactly determines the other (this is not intended to be a precise distinction of the two). Thermal photons on the other hand no longer become correlated when the detection time is shorter than the pathlength difference (paths distinguishable). The term entanglement is thrown around far to often when it shouldn't be. If these are thermal correlations, would the paper "thermal correlations of two diamonds" got as much attention.
Reply | Report Abuse | Link to thisThe authors in the abstract state 98% but in the discussion seem to say this is not viable because of noise , etc. If it was it would be entanglement. They state the basis of saying it is entanglement is figure 3 (not exactly what the abstract is pushing) which is challenging to interpret with the limited information.
Reply | Report Abuse | Link to thisAgain, the ~15 cm separation distance restriction between diamond wafers of millimeter size seems to violate any classical qualification of quantum entanglement, which has been demonstrated to persist across distances of many kilometers separated by many kilometers. While these separation distance limits may seem inconsequential to researchers in quantum computing devices, if the separation distances are so limited the rang of potential applications are also severely restricted.
Reply | Report Abuse | Link to thisBTW, I did find access to the article's supplemental material is freely available at: Supporting Online Material for "Entangling Macroscopic Diamonds at Room Temperature", http://www.sciencemag.org/content/suppl/2011/11/30/334.6060.1253.DC1/Lee.SOM.pdf
The (very small) figures are freely available.
This report has also been cited by another report: "Quantum Correlation Between Distant Diamonds", http://www.sciencemag.org/cgi/content/summary/334/6060/1213
Curiously, the 'distant diamonds' report also shares the ~15 cm separation distance restriction...
I am confused by your comment. Quantum physics doesn't put a distance limit on quantum entanglement or any other quantum correlations. My point is this is likely quantum correlation and not true quantum correlations.
Reply | Report Abuse | Link to thisI also do not understand why you are referring to the science magazine review of the original article. These are news articles of the original science article. Did you think they were separate publications?
Sorry, the sentence should read this is likely thermal quantum correlations and not true quantum entanglement.
Reply | Report Abuse | Link to thisMy intended point is that quantum physics doesn't put a distance limit on quantum entanglement - this experiment does and does not therefore qualify as quantum entanglement. This seems to agree with your point.
Reply | Report Abuse | Link to thisI'm confused by your question about my reference to the Sicence magazine article. This article on the scientificamerican.com site (a division of Nature America, Inc.) is a news report reviewing a research report published in Science magazine. The research report is also available online to members of the American Association for the Advancement of Science at its sciencemag.org site. You referenced a "fig. 3" in a previous comment, which I could only find on the sciencemag.org site. Did I miss something? If not, I still think these are separate publications.
By definition antimatter is simply another configuration of subatomic particles so your entire philosophy is based on bad vocabulary.
Reply | Report Abuse | Link to thisSince I really don't understand quantum physics even though I can throw some of the terms around, I'm going to challenge the assertion of the article procedurally rather than scientifically.
Reply | Report Abuse | Link to thisMy point is this;
If the splitter separates the beam which then passes through the 2 diamonds and the detector detects only 1 phonon, were the 2 beams merged after passing through the diamonds or where they collected seperately? To get a valid response you would have to try it both ways. If combining the 2 beams gets only 1 phonon detected and collecting them seperately also gets 1 phonon, what would that mean? Would the detectors detect half a phonon each? If not then the single phonon would come only from 1 side thus proving no entanglement. Also what happens if you split the beam but only half goes through a diamond? Do you get a different result or the same result? What would either result mean? I'm pretty sure that this experiment isn't exactly thorough in testing all of the variables.
This seems very much like they decided what they want to be true and then designed an experiment the get the evidence they wanted instead of using empirical observation. JT is quite correct when he points out the distance limitation as well. Everything I've read previously states quite clearly that entangled particles have been separated by kilometers instead of centimeters.
I also have a problem with the uncertainty principle stating that Schrodinger's cat is both alive and dead at the same time. That is simply stupid. We don't know if the cat is alive or dead, hence the uncertainty. The cat may be in either state or have been rescued by animal rights activists. Until we open the box we can't tell. This doesn't make the cat alive and dead at the same time. It just makes us ignorant of the actual, factual state of the cat.
Since the end result is the same either way; we can't rely on either state being true, isn't it better to be accurate and simply say we don't know and can't find out without doing something that removes the uncertainty? Saying that something with 2 possible states is in both states at the same time violates the entire concept of states.
Getting back to the cat analogy - when the box starts stinking like dead cat, the uncertainty is pretty much gone.
Well done.
Reply | Report Abuse | Link to thisI'm no physicist or mathematician either - I'm just a simple retired information systems analyst. As I understand, the Einstein–Podolsky–Rosen paradox states:
Entangled "particles" are emitted in a single event. Conservation laws ensure that the measured spin of one particle must be the opposite of the measured spin of the other, so that if the spin of one particle is measured, the spin of the other particle is now instantaneously known.
I don't know how the 'immediate remote transfer of information' interpretation of quantum physics can be experimentally distinguished from a simple state predetermination interpretation. In other words, physicists know that the particle spins must be of opposite states because of conservation laws: a simple interpretation is that the spin state of both particles is determined at the moment a single particle is split into two entangled particles. In this case no immediate exchange of remote information or control is necessary: measurement of one particle's probabilistic state does not at that moment determine the remote particle's state: it was probabilistically predetermined when the originating particle was split.
As an information systems analyst, perhaps particle physicists have produced too much of their own information to interpret their results simply while maintaining consistency with prior interpretations...
I'm not the only one hearing the dual-wafer experiment(dual-slit experiment)? He even said the photon and phonon paths interfered with the other. So, entanglement also creates the dual-slit experiment and it does go through both slits.
Reply | Report Abuse | Link to thisI read about a quantum linked photon telescope that picks up photons from quasars through clouds, but have excellent pictures because of the quantum linked photons. Isn't this entanglement? Photons traveling through space at "C", timeless and massless. When measured time begins instantaneuosly with opposing spins and infinite mass along its entire time/mass front(static-magnetic). I've read photons are plasma created from magnetic fields. A magnet traveling through space will rotate negative particles but the magnetic wont be effected, what happened to equal and opposite reaction? Magnetic energy rules!
The lattice of the diamonds where the same, like similar tuning forks one starting another. How does that work no losses in the transfer of waves though air or macro entanglement of similar lattice? Instantaneous travel between similar lattice using entanglement?
Waves of light creating time, gravity and infinite entanglement Universally.
Thanks