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D-Wave Quantum Computing Solution Raises More Questions

Soulskill posted about 9 months ago | from the may-or-may-not-be-D-wave-of-the-future dept.

Science 143

benonemusic writes "The commercially available D-Wave computer has demonstrated its ability to perform increasingly complex tasks. But is it a real quantum computer? A new round of research continues the debate over how much its calculations owe to exotic quantum-physics phenomena. 'One side argues there is too much noise in the D-Wave system, which prevents consistent entanglement. But in an adiabatic device, certain types of entanglement are not as vital as they are in the traditional model of a quantum computer. Some researchers are attempting to solve this conundrum by proving the presence or absence of entanglement. If they show entanglement is absent, that would be the end of the discussion. On the other hand, even if some of D-Wave's qubits are entangled, this doesn't mean the device is taking advantage of it. Another way to prove D-Wave's quantumness would be to confirm it is indeed performing quantum, and not classical, annealing. Lidar has published work to this effect, but that triggered opposition, and then a counter-point. The debate continues.'"

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143 comments

entangled entanglement (5, Insightful)

aleator (869538) | about 9 months ago | (#45177939)

how do you show the presence of entanglement without disturbing it?

Re:entangled entanglement (0)

Anonymous Coward | about 9 months ago | (#45177985)

Don't look at it.

Re:entangled entanglement (0)

Anonymous Coward | about 9 months ago | (#45178061)

Sneeze on it. If it gets mad at you, you are to be sure it is in-tangled.

Re:entangled entanglement (0)

Anonymous Coward | about 9 months ago | (#45179363)

Whatever that joke was, it's so inside that it's never coming out.

Re:entangled entanglement (-1)

Anonymous Coward | about 9 months ago | (#45179419)

I'm inside your mom and the only joke coming out is your little half-brother in 9 months.

Re:entangled entanglement (4, Funny)

Frosty Piss (770223) | about 9 months ago | (#45178069)

how do you show the presence of entanglement without disturbing it?

You ask Schrodinger's cat. He has the answer...

Re:entangled entanglement (2)

Austrian Anarchy (3010653) | about 9 months ago | (#45178083)

how do you show the presence of entanglement without disturbing it?

Analyze it with a quantum computer.

Re:entangled entanglement (0)

Anonymous Coward | about 9 months ago | (#45178293)

All I know is that it keeps you from blacking out during a flash-forward.

Correlation (3)

Roger W Moore (538166) | about 9 months ago | (#45178859)

Measure correlations between the two systems. If you have entangled, oppositely polarized photons and you simultaneously pass them through aligned polarizers then one will always pass through the filter and one will always fail. It is impossible to recreate this in any classical system without communication between the photons.

If you can perform the same type of measurement with entangled qbits in a manner where it is physically impossible for them to communicate (e.g. make the two measurements simultaneously) you can confirm their quantum nature.

Re:Correlation (1)

aleator (869538) | about 9 months ago | (#45180843)

elegant solution! ... but how do you do it inside the D-wave? if you want it to work as a "computer" (which is a bit a misnamer if quantum is involved), you would have to manipulate the machine itself to be able to determine bells signal or in your suggestion the passing.

Re:Correlation (1)

Roger W Moore (538166) | about 9 months ago | (#45182031)

elegant solution! ... but how do you do it inside the D-wave?

Good question but I simply don't know enough about the D-wave to be able to answer. My point was just that it is possible, in principle, to devise such a measurement but how to do that in practice will depend heavily on the details of the D-wave.

Re:Correlation (1)

aleator (869538) | about 9 months ago | (#45182133)

i'm also not familiar with the inner workings of d-wave... but in general since we would have anyway always a non-quantum and quantum computer mixture, an indicator of the qubits used for a process might be of use!

Re:entangled entanglement (4, Informative)

edelbrp (62429) | about 9 months ago | (#45179251)

You can do what Alain Aspect did which was to show that statistically a system can show the repeatable statistical measurements (using Bell's Theorem) that indicate that entanglement is happening. Then let the system/computer do it's thing with some confidence that entanglement is in play.

Re:entangled entanglement (4, Informative)

drolli (522659) | about 9 months ago | (#45179577)

Experimentally entanglement is shown most strongly in the form of Bell violations:

http://en.wikipedia.org/wiki/Bell's_theorem [wikipedia.org]

as e.g.

http://www.nature.com/nature/journal/v461/n7263/abs/nature08363.html [nature.com]

did.

Re:entangled entanglement (1)

aleator (869538) | about 9 months ago | (#45180855)

thanx for the paper - its quite interesting, but not part of a running computer. also the bell signal would be changing from state to state of d-wave. quantum computers need a indicator of the bells signal (or rather CHSH signal) at the moment of computation! we should make it a nice colourful display in front to show you how much "quantified" you are computing atm ;)

Re:entangled entanglement (0)

Anonymous Coward | about 9 months ago | (#45179719)

"Some researchers are attempting to solve this conundrum by proving the presence or absence of entanglement. "

Entanglement can not be proven or disproven, it can only be catsproven

Re:entangled entanglement (1)

slashmydots (2189826) | about 9 months ago | (#45181877)

Simple. Make it do something only a quantumly entangled system could do in a given time period like reverse factorization or whatever. So far, they haven't done that. Their excuse is a lack of sufficient quantities of qubits to determine a speed change in factorization. Basically a normal CPU or ASIC could have solved the equation they demonstrated in 1 ms but a quantum one could solve it in a billionth of a millisecond but you can't measure that small of a time frame so you have to take their word on it that the machine didn't fake it. Go up to 4x the qubits and tada, it can crack and encryption key virtually instantly and prove itself.

Who needs D-Wave anyway? (1)

olsmeister (1488789) | about 9 months ago | (#45178023)

We have Google. [slashdot.org]

Re:Who needs D-Wave anyway? (0)

Anonymous Coward | about 9 months ago | (#45179561)

We have Google. [slashdot.org]

Google have a D-Wave machine, maybe this is what they use it for :)

Re:Who needs D-Wave anyway? (1)

aleator (869538) | about 9 months ago | (#45180869)

so that they can be uncertain about our personal data?

Sounds like a scam, quite frankly (3, Interesting)

Impy the Impiuos Imp (442658) | about 9 months ago | (#45178033)

Can someone explain to me how this chip could be calculating anything unless the quantum part was working?

Isn't it like a car that has an electric motor or a gas one, but not both? How can they be confused which engine is running? Who builds a backup normal processor then what, it fills in if the quantum one doesn't work right, and they have no way to tell if this backup kicked in?

Re:Sounds like a scam, quite frankly (0)

Anonymous Coward | about 9 months ago | (#45178103)

Well, it's more like a car that has both an electric and gas motor, and the car moves forward, but it's undefined which motor is providing the motive power unless you open the hood and look.

Re:Sounds like a scam, quite frankly (5, Informative)

InfiniteLoopCounter (1355173) | about 9 months ago | (#45178105)

Can someone explain to me how this chip could be calculating anything unless the quantum part was working?

D-wave is very secretive about how their machine operates and do not respond to academics who want to know exactly how it works -- this is the source of much of the speculation. On top of that you need to specially code your instructions for it, because it can only do a subset of what a general quantum computer could in theory do.

Re:Sounds like a scam, quite frankly (3, Informative)

quax (19371) | about 9 months ago | (#45178869)

You are a bit behind the times. This was true as long as D-Wave was in stealth mode.

At this point they are quite open and have published several papers in Nature.

Re:Sounds like a scam, quite frankly (5, Informative)

HuguesT (84078) | about 9 months ago | (#45178127)

The D-Wave engine can indeed solve some specific optimisation problems by a method called adiabatic annealing. Essentially this done by encoding the problem to be solved in some initial state of the physical components of the engine, and letting it evolve without exchanging energy with the outside world (this is what adiabatic means). The evolution is done in such a way that the solution to the optimisation problem eventually appears (this is the annealing part) with some probability.

The engine definitely works, this is not disputed. However there is some debate whether the way the engine works is essentially classical or essentially quantum. At the moment the engine is not especially powerful and it is very noisy, so there is no easy way to tell. In the 3 papers cited in the Fine Article, one says this is definitely quantum because the way the system evolves does not match the way classical annealing is simulated (simulated annealing (SA) is a very popular way to solve some complex classical optimisation problems). The second paper says that it is still possible to achieve the signature observed in the first paper by purely classical means, so this is not so clear. The third papers says that this is correct, but that there is more to the signature than was reported in the first paper, and that *this* is more likely to be quantum than not.

Feel free to contradict me. At any rate, and this is not disputed, the D-Wave engine does not work in the way quantum computers are expected to work in the literature about this topic. It would not be useful to solve factorisation problems as in the Shor algorithm [wikipedia.org] . Rather, it would be useful to solve some optimisation problems in a faster way than with classical or traditional CPUs or GPU. This is still very useful, although at the moment the D-Wave computer's inner working are mostly secret, not hugely fast, and noisy. So D-Wave's qbits are a bit of a misnomer. They should be called something different so as not to engender confusion, perhaps obits (optimisation bits)?

I hope this make sense to you.

Re:Sounds like a scam, quite frankly (0)

Anonymous Coward | about 9 months ago | (#45178225)

You sound like you know this topic. I have a question for you, just for personal curiosity.

Is there any known possible use for quantum computers besides Shor's algorithm, or the other one I saw where it can find a row in a database table by a single lookup (I don't remember the name of that one).

I was just curious, becasue there seems to be a lot of research into it with only a couple of possible application. Maybe they are expecting new applications for it to emerge once they have one working.

Re:Sounds like a scam, quite frankly (1)

sanpitch (9206) | about 9 months ago | (#45178573)

I think the search that you refer to is Grover's algorithm: https://en.wikipedia.org/wiki/Grover's_algorithm [wikipedia.org]
Yes, Quantum computers have other known uses besides Shor's and Grover's algorithms. Specifically, they can simulate other quantum systems, and also do a few other things such as solving algorithms based on quantum walks. See https://en.wikipedia.org/wiki/Quantum_algorithm [wikipedia.org]

I have a similar question to yours. Do the D-Wave people claim any mapping of their hardware to a known quantum algorithm such as those at the last link above, or what?

Re:Sounds like a scam, quite frankly (2)

quax (19371) | about 9 months ago | (#45178911)

No, the D-Wave machine can only solve the Ising equation. Universal adiabatic quantum computers have been shown to be able to emulate gate model quantum algorithm, but for the more restricted current D-Wave architecture a mapping is (probably) not possible. Nevertheless the class of problems they can solve is still pretty large, and is applicable to useful optimization use cases and learning algorithms.

Re:Sounds like a scam, quite frankly (3, Insightful)

Garridan (597129) | about 9 months ago | (#45178247)

Yeah... I watched a talk by a D-Wave guy. This is a summary of his talk: "So, you have an NP-Complete problem. We have a quantum solver that works on a large graph with a special structure. If you can find a homomorphism from your problem into our graph structure, and you can figure out how slowly to evolve the adiabatic process, then we can solve your problem!"

Okay, that's great. But finding that graph homomorphism? Probably NP-Complete itself. Figuring out how slowly to evolve the system? I have no idea, but the guy said "it's hard", which means the physicists don't have any idea. Maybe also NP-Complete or worse? Who knows. Tell ya one thing, D-Wave sure doesn't.

Re:Sounds like a scam, quite frankly (3, Interesting)

HuguesT (84078) | about 9 months ago | (#45179781)

Theoretical Quantum computer using entanglement to perform their calculations make no claim to solve NP-hard problems. They can only solve some very specific class of problems, that are well identified but are still interesting. Integer factorisation is one of them, but factorisation is not thought to be in NP-complete [wikipedia.org] , although we are not certain at this stage.

There is an old article in PNAS that says that adiabatic quantum computers are theoretically no better [pnas.org] than classical computers at solving NP-hard problems. So even if D-Wave had a truly working adiabatic quantum computer, it is not clear that it would perform orders of magnitudes better than what we have now.

Anyway all of this is very interesting to watch, but the fact that D-Wave is so secretive is not very compatible with progress in the field.

Sounds like a falsification problem (0)

Anonymous Coward | about 9 months ago | (#45178345)

"At any rate, and this is not disputed, the D-Wave engine does not work in the way quantum computers are expected to work in the literature about this topic."

There are two options: Reality has refuted the literature. Or D-Wave did not engineer their system in accordance with the literature. That last is, or should be, trivial to rule in or out.

If it was engineered properly, then reality rules supreme. If it was not, then we're still all agreed that it's a quasi-quantum device. Where quasi-quantum is indistinguishable from a really fast guy with an abacus.

Re:Sounds like a falsification problem (1)

gl4ss (559668) | about 9 months ago | (#45179243)

There are two options: Reality has refuted the literature. Or D-Wave did not engineer their system in accordance with the literature. That last is, or should be, trivial to rule in or out.

well, what dwave did was build what they could and called it quantum computing.

and sell it for big bucks to organizations which hope the next generation will have practical use.

Re:Sounds like a scam, quite frankly (0)

Anonymous Coward | about 9 months ago | (#45178581)

I think it's very, very, very improbable that the D-Wave engine is...wait, where did all these fried eggs come from?

Re:Sounds like a scam, quite frankly (2)

gweihir (88907) | about 9 months ago | (#45178129)

Ordinarily, you would look at the computing power. If it is significantly larger than conventional physics can explain, it must use quantum effects. Unfortunately, this "magic black box" is in no way faster than traditional computers, just a lot more expensive, hence the hand-weaving.

My money is on this being pure fraud. Would not even surprise me if there is a conventional computer hidden in there somewhere that does the calculations.

Re:Sounds like a scam, quite frankly (2)

HuguesT (84078) | about 9 months ago | (#45178153)

I'm personally reasonably convinced that D-Wave's engine is novel and does offer some new ways of performing various specific calculations. The literature about it exists and is quite interesting for people interested in optimisation. However I'm not sold to the technology yet, essentially classical CPUs can perform the same type of calculation that D-Wave's computer can at the moment, at a much lower cost. This might change in the future though.

Re:Sounds like a scam, quite frankly (3, Informative)

quax (19371) | about 9 months ago | (#45178921)

I recently visited D-Wave looked at their chips and deep freeze containment. Shot a snapshot of Geordie Rose standing in one of the open boxes. [wavewatching.net]

You may think they are misguided, but their tech is for real. Even Scott Aaronson doesn't deny that.

There is no classical computer hidden inside, but there is still reasonable doubt as to exactly how quantum the device is, and if it will ever deliver clear cut quantum speed-up.

Re:Sounds like a scam, quite frankly (1)

fatphil (181876) | about 9 months ago | (#45179695)

Whoever wrote that article has absolutely no interest in communicating clearly.

When such people are supportive of D-Wave, it adds no credibility to D-Wave at all. If anything, it reinforces the prejudices that many have against them.

So, they've left "stealth" mode, and are now in full-on "buzzword bingo" mode?

Re:Sounds like a scam, quite frankly (2)

gweihir (88907) | about 9 months ago | (#45180147)

You do realize that you can put classical computers on deep-frozen chips, do you? And that they tend to run _very_ fast in that situation?

Re:Sounds like a scam, quite frankly (1)

quax (19371) | about 9 months ago | (#45180829)

That'll be a lot of effort for a fraud, especially since you then have to fake all the qubit specific data that goes into the publications. And the chip samples they have on display very much looks like Josephson junctions circuits and nothing like regular chips. (And the integration density they have for this process could not at all deliver reasonable classical performance).

Re:Sounds like a scam, quite frankly (1)

gweihir (88907) | about 9 months ago | (#45181415)

And do you realize that Josephson circuits are especially fast and well understood, if not cost-effective? And that in addition there does not need to be any resemblance between what they display publicly and what is actually in the machine? And that what is actually in the machine does not need to be created with the same process or by them at all? Until somebody competent in detection technological fraud disassembles one of these, we do not know. I bet disassembly voids the warranty or even destroys the thing! I also bet that anybody buying one of these is under a very strict NDA that disallows disassembly for any purpose.

No, the effort needed to defraud is not an indicator of the presence or absence of fraud. The ratio between grand claims and poor delivery at high prices is a pretty strong indicator of fraud, as is the refusal to explain the details. Can be observed in a far more crude version in other tech-fraud cases, like the Rossi cold fusion device (http://en.wikipedia.org/wiki/Energy_Catalyzer). That one is still going strong despite the obviousness of his fraud.

Re:Sounds like a scam, quite frankly (1)

quax (19371) | about 9 months ago | (#45181759)

I've been following the Rossi story as well and agree that it is a fraud, but the comparisons to the ecat are only superficial. [wavewatching.net]

The contraptions Rossi builds are cheap and look like a plumber put them together. On the other hand D-Wave has chips samples on display that are produced by a special purpose foundry that can produce Niobium SC circuitry. That took some serious investments.

Rossi supposedly sold his house to finance his venture, D-Wave is backed by the likes of Steve Jurvetson and Jeff Bezos. Rossi has phantom customers who don't talk to the public, D-Wave has Google, NASA and Lockheed Martin.

Frankly, after they started publishing in Nature it's ludicrous to hang on to the idea that this is just an elaborate fraud. Then again conspiracy theories are a dim dozen on the Internet, and you are free to believe whatever you want.

Re:Sounds like a scam, quite frankly (1)

gweihir (88907) | about 9 months ago | (#45184419)

Nature has been duped before. They are just better fraudsters than small-time Rossi is.

Re:Sounds like a scam, quite frankly (1)

quax (19371) | about 9 months ago | (#45184943)

Well then they duped them more than once and also duped Phys. Rev. A and B. Phys. Rev. Lett.

http://www.dwavesys.com/en/publications.html [dwavesys.com]

Sorry pal, but you may as well subscribe to creationism. They have an adiabatic chip, the only open question is how good it is.

Re:Sounds like a scam, quite frankly (1)

quax (19371) | about 9 months ago | (#45185239)

Maybe you should post some of your concerns to this reddit group [reddit.com] that has people who actually work with D-Wave boxes.

Re: Sounds like a scam, quite frankly (0)

Anonymous Coward | about 9 months ago | (#45180713)

They are a government contractor.., there was once a firm that sold snake oil gas additive to the Australian government that supposedly raised mileage of their cars, and the scheme would be running to this very day without scientists' inquiry and public outcry.

D-Wave - quantum computer powered by cold-fusion ? (0)

Anonymous Coward | about 9 months ago | (#45178039)

There are a lot of talk about D-Wave, but from what I was able to gather, it seems like like whole things is covered under veil of secrecy. Why so much secrecy ?
So, is D-Wave a real deal or it is quantum computer powered by cold-fusion ?

Re:D-Wave - quantum computer powered by cold-fusio (2)

quax (19371) | about 9 months ago | (#45178937)

The secrecy pretty much went away when they came out stealth mode.

Now they published several papers in Nature and are quite open.

When I visited them I was surprised that there were no restrictions on taking pictures and nothing was off limits.

Hasn't the benchmarks put it above anything? (1)

Anonymous Coward | about 9 months ago | (#45178045)

Hasn't the benchmarks already placed it above pretty much any computer in the tasks it can do within its full size?

Mind you, I guess even if that were true, if it wasn't quantum entanglement taking place, it would still be pretty big because they still managed to find a way to make a non-quantum computer way ahead of the competition.

If it is a quantum processor, it would be similar to say... the math co-processor, still baby steps towards a full, integrated circuit.
They even say themselves that it is only useful for certain tasks, some which are highly useful to certain people doing largely complicated, inter-connected lookups.
No wonder Google are interested in it, if it worked and they were the ones working on it and helping research it, they'd benefit hugely in their search systems, be it regular old text search of image-matching. That plus their machine-learning systems would be insane. (also very useful for NASA to spy on planets. And NSA to spy on people)

Re:Hasn't the benchmarks put it above anything? (1)

gweihir (88907) | about 9 months ago | (#45178109)

Last state of my knowledge is it is slower than a traditional computer in a fair comparison. There are some benchmarks though that have a traditional computer simulate this thing, and, not surprisingly, the simulation is slower than the real thing. That is about the most unfair comparison possible though.

Re:Hasn't the benchmarks put it above anything? (3, Informative)

the gnat (153162) | about 9 months ago | (#45178411)

Hasn't the benchmarks already placed it above pretty much any computer in the tasks it can do within its full size?

My understanding was that the benchmarks - at least the one that was quoted as showing a "3600x speedup" - weren't even comparing the same thing: the D-Wave computer was running the quantum adiabatic annealing method, which is the only way it can be programmed, while the conventional CPU was running an exact solver. The latter is expected to be vastly less efficient (but more precise). When a group of computer scientists came up with an annealing method to solve the same problem on a conventional CPU, they ended up with something just as fast as the D-Wave system.

Re:Hasn't the benchmarks put it above anything? (3, Interesting)

quax (19371) | about 9 months ago | (#45178895)

The benchmark did indeed not demonstrate a quantum speed-up, but it in fairness to D-Wave this was a test designed based on the customers requirements i.e. for them acing this benchmark was good enough to justify investing in this technology.

My understanding is that the algorithm that was comparatively fast on a classical computer was hand optimized by a graduate student, it was not a generic annealing algorithm solver.

But the paper on this effort of 'beating' D-Wave on a classical machine is yet to be published, so this is all from blog hearsay.

Re:Hasn't the benchmarks put it above anything? (3, Interesting)

amaurea (2900163) | about 9 months ago | (#45179603)

Could you elaborate a bit on this? I had the impression that D-Wave's users had to map their problem to fit what D-Wave computes, not the other way around. That would make comparisons with a specialized software solver appropriate, wouldn't it?

The blog post in question [archduke.org] also includes a link to the source code [github.com] of the specialized solver (Prog-QAP), and others have confirmed that it produces the same results as CPLEX, the general solver that D-Wave beat.

CPLEX is indeed slower than D-Wave, though newer versions have brought the factor down from 3600x to 14x [ibm.com] . But again, CPLEX is a general solver, while D-wave is specialized hardware. The specialized software solver Prog-QAP is *much* faster than CPLEX, and gets a 12000x speedup over D-Wave when running on a single core.

But all of that is a bit old, and it may be that D-Wave has produced more impressive results after that. I hope D-Wave's approach results in something able to beat classical computers, even if it doesn't lead to a general quantum computer. But I really dislike all the secrecy they employed - that is not how science is supposed to work. The fraud speculations they have had to endure are entierly self-inflicted due to this secrecy.

Re:Hasn't the benchmarks put it above anything? (1)

quax (19371) | about 9 months ago | (#45180963)

I was referring to the paper by Mathias Troyer et. al. that is yet to be published not the effort that Alex Selby writes about (thanks for the link).

Will have to read the latter in more detail to get a good grasp of how much effort is required to beat the benchmark with Alex's approach. Two caveats: On first glance I am not sure if he has the same training data (he mentions he communicated with Cathy McGeoch) - if he does it'll be interesting to see how stable his generic approach is when the problem domain is slightly altered.

Do you know if he plans to publish any of this?

Has it gotten faster than traditional computers? (0)

gweihir (88907) | about 9 months ago | (#45178095)

I doubt it. It is however far more expensive and is making its "inventors" a tidy profit at zero benefit to those stupid enough to buy one.

marketing for Intel (0)

globaljustin (574257) | about 9 months ago | (#45178149)

the 'race' to quantum computing is all about Marketing: "Now with QUANTUM technology!"

everyone wants to be the computing/physics genius who 'ushers humanity into a new era of computing'....someone might mention the 'singularity'

properly understood, Quantum Entanglement is at the core of all Quantum Physics [wikipedia.org]

if a research group **truly** were able to maintain a standing quantum entangled state with **non-local force transfer** and **quantum teleportation of information** [wikipedia.org] then that would be, essentially, the **single greatest physics accomplishment of all human history**

I want it to happen. I think it will. I think it is not the same thing as the 'singularity' but that some people do...

The point is, what these Quantum Computing research groups are doing has nothing to do with harnessing the mysterious forces of nature or testing hypothesis proper....this is standard, state-of-the-art microprocessor research gussied up with hyperbolic language

Re:marketing for Intel (2)

Roger W Moore (538166) | about 9 months ago | (#45178879)

properly understood, Quantum Entanglement is at the core of all Quantum Physics [wikipedia.org]

No it is not. It is one of the features of quantum physics which is the hardest to understand and, arguably, we still do not have a good grip on it. However that by no means puts it at the core of all quantum physics: there is far more to QM than quantum entanglement e.g. tunnelling, self interference etc.

Einstein & Schodinger accept your apology (0)

globaljustin (574257) | about 9 months ago | (#45178971)

did you check the source of my claim? go ahead...fine if you're just that impatient I'll paste it below...

it has some pretty good scientific backing:

Research into quantum entanglement was initiated by a 1935 paper by Albert Einstein, Boris Podolsky, and Nathan Rosen describing the EPR paradox[13] and several papers by Erwin Schrödinger shortly thereafter.[14][15] Although these first studies focused on the counterintuitive properties of entanglement, with the aim of criticizing quantum mechanics, eventually entanglement was verified experimentally,[16] and recognized as a valid, fundamental feature of quantum mechanics. The focus of the research has now changed to its utilization as a resource for communication and computation.

[13] Einstein A, Podolsky B, Rosen N (1935). "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?". Phys. Rev. 47 (10): 777–780. Bibcode:1935PhRv...47..777E. doi:10.1103/PhysRev.47.777.

Re:Einstein & Schodinger accept your apology (1)

Nemyst (1383049) | about 9 months ago | (#45178993)

Controversial for a while? Yes. Fundamental? Yes, At the core? Not necessarily. QM involves a lot of things and entanglement is only part of that.

Re:Einstein & Schodinger accept your apology (1)

Roger W Moore (538166) | about 9 months ago | (#45179047)

did you check the source of my claim?

Yes, but do you understand it? There is a huge difference between being a "feature of QM" (as your source accurately states) and being "at the core of QM" as you incorrectly state. Entanglement is a feature of QM but there are many other features of QM that have nothing to do with entanglement.

you misquoted my quotation directly heres proof (0)

globaljustin (574257) | about 9 months ago | (#45179165)

I'm not playing anymore...you misquoted my quotation here:

"feature of QM" (as your source accurately states)

No, actually, **one part** of the wikipedia portion copied (with the actual source below) **correctly** states the following (emphasis added)

recognized as a valid, fundamental feature of quantum mechanics

And, i'm definitely not going to get into the difference between being **AT** the core of something (which I said) and being **THE ONE AND ONLY** core of something (what you're trolling me to have said)...

and being "at the core of QM" as you incorrectly state.

I'm letting the community handle this from here (cant mod on my own discussion of course)

Re:you misquoted my quotation directly heres proof (1)

ldobehardcore (1738858) | about 9 months ago | (#45179301)

properly understood, Quantum Entanglement is at the core of all Quantum Physics

To a US English speaker, this phrase can generally be translated to mean "All quantum mechanical reasoning relies on quantum entanglement" which is false. But the phrase you state leaves room for interpretation and can certainly mean "quantum entanglement is one of the basic features of quantum mechanics" or even "quantum mechanics requires quantum entanglement to be true". It's just that the standard way the phrase is parsed makes it seem you're saying entanglement is the most important or most fundamental feature of quantum mechanics. You aren't wrong, but the way you expressed yourself can be a little confusing.

Deep breaths (1)

Roger W Moore (538166) | about 9 months ago | (#45179321)

I did not misquote you: a fundamental feature is just one that derives from the fundamental nature of quantum mechanics. That does not mean that it is central to the nature of quantum mechanics. To use an example from my own field of particle physics I could correctly say that kaon oscillations are a fundamental feature of particle physics but it would be ludicrous to say that this are "at the core" of particle physics.

So you might want to take a deep breath and calm down a little. Trying to claim that there are multiple "cores", when core is generally taken to mean "centre", sounds like you are desperately flailing around trying to justify yourself. Massive use of asterisks coupled with claiming that discovery of quantum teleportation of information (which has already been shown) would be "single greatest physics accomplishment of all human history" isn't exactly helping your case either.

I'm letting the community handle this from here (cant mod on my own discussion of course)

No, but going on past experience with comments like this undoubtedly your friends and/or secondary accounts can unfortunately.

So long, and thanks for all the quarks... (0)

Anonymous Coward | about 9 months ago | (#45178257)

"Yet even tiny amounts of noise can cause a quantum state to lose coherence, "

Signal to noise ratio decreases as you get smaller (and approaches 0 rapidly) leaving anything at the 'quantum' qubit level useless (scale it up and it reverts to 'classical' logic (and we already have far cheaper mechanisms fo doing it that way...)

 

Just do it. (4, Interesting)

CanEHdian (1098955) | about 9 months ago | (#45178287)

There should be plenty of problems a quantum computer could solve in polynomial time that would take classic computers eons to solve. Start solving those problems and it's a quantum computer. Simple as that.

Re:Just do it. (2, Informative)

edelbrp (62429) | about 9 months ago | (#45179267)

They have. We're still waiting for the classical computers to finish to compare answers. Should just take a few eons. Then we'll know it works.

Re:Just do it. (1)

AmiMoJo (196126) | about 9 months ago | (#45179475)

Exactly, it doesn't really matter if it is a real quantum computer or not, only that it can complete certain computations that people need much faster than a traditional computer. If it solves that problem for someone then the rest of the debate is academic.

Re:Just do it. (1)

multimediavt (965608) | about 9 months ago | (#45180115)

Exactly, it doesn't really matter if it is a real quantum computer or not, only that it can complete certain computations that people need much faster than a traditional computer. If it solves that problem for someone then the rest of the debate is academic.

Wait, it does matter whether this is a quantum computer or not. If it *is* a quantum computer then the calculations can be trusted to be accurate and precise based on the fundemental principles driving the solutions. If it is *not* a quantum computer all the results from the machine may be so horribly wrong that they cause serious accidents, damage or loss of life. The problem as stated above in the comments is that some of the calculations take so egregiously long ("eons") on traditional computation devices that we will have no way to verify them for decades if not centuries. That's a real problem that QC needs to solve before it can be trusted. I don't know where the ball sits right now, but from all the fervor I'd say the jury is still out on whether the Dwave machine results can be trusted. I am skeptical, but hopeful. It sure would be nice to have QC working sooner than later. But, trust is still out on this whole deal and is the real sticking point for the physicists and mathematicians that are challenging the current tech. How do we really know if some of the results the Dwave machine cranks out are correct if we don't have known results to point to? That was rhetorical, I know the answer to that question, btw.

Re:Just do it. (1)

AmiMoJo (196126) | about 9 months ago | (#45180415)

That's not how quantum computers work or how they are used. You don't get a definite answer, just a highly probable one. You then have to verify it with a normal computer. The problem that the quantum computer solves is that a normal computer has to try every verifying possible answer until it finds the right one. Each test may only take fractions of a second, but you have to do so many of them it takes an unreasonable amount of time.

what bullshit. you know the answer (0)

Anonymous Coward | about 9 months ago | (#45178321)

Stop the riddles, it gets old fast.

DWave itself is in an indeterminate quatum state (3, Interesting)

Required Snark (1702878) | about 9 months ago | (#45178343)

Consider the hypothesis that the DWave machine is a superposition of classical and quantum computing. By some observations it is classical, by others quantum. As some point a measurement will be preformed on the machine, and it's state will resolve into either a classical physics computing device or a quantum physics computing device.

This situation is completely reasonable give the current state of the art in quantum computing.

Making accusations of "marketing hype" and unethical behavior are irrelevant. Whatever it's doing, it's not digital computing. Even if it turns out to be classical physics, it is still advancing the state of the art in non-digital computing.

No matter how DWave does in the future, quantum computing is still going to happen in the near term. Dwave is not going to change that under any circumstances.

Getting bent out of shape over this is a waste of effort. Even the experts are not in agreement. This is how progress occurs at the cutting edge.

Used to think it was a scam, not so sure now (0)

Anonymous Coward | about 9 months ago | (#45178359)

There is a deep misunderstanding of the general public about how metaheuristics such as simulated annealing and its variants such as quantum annealing (http://en.wikipedia.org/wiki/Quantum_annealing) works. Basically, you can't compare the output of D-Wave with another, classical, machine and say for sure if there are quantum effects involved or not, you'd need access to the internal workings to say that 100% positively.

Quantum computation can easily be simulated in a classical computer, albeit it loses *almost all* of the nifty properties of a real quantum computer it retains, to some degree, the qualities in estimation of distributions.

When D-Wave was first announced me and a few research colleagues made a bet, we bet D-Wave was based on a traditional computational hardware ***inspired*** by quantum computation, without actually using any quantum effects. An analogy would be all the neural net chips these days without a biological neural net.

In the scenario of our bet, both the processor and the quantum bits are actually well implemented simulations of a quantum computer. In fact, it's a CPU especially crafted for estimation of distributions. This would account for the observed high error rates and noise.

These days, I'm not so sure anymore.

Either the "simulated quantum" hardware is incredibly good or it really uses quantum effects. I can't believe Google and other major companies would invest in a hoax.

Re:Used to think it was a scam, not so sure now (1)

koan (80826) | about 9 months ago | (#45178509)

This stuff is a bit dense for me (or me for it) but wouldn't this be considered a biological neural net:
http://news.discovery.com/tech/robotics/brain-dish-flies-plane-041022.htm [discovery.com]

Or did I completely misinterpret what you were saying in your comparison.

Re:Used to think it was a scam, not so sure now (0)

Anonymous Coward | about 9 months ago | (#45178815)

Yes, that's a biological neural network, just as much as our brain is.

However, you did misinterpret. I was refering to neural nets in integrated circuits.

http://en.wikipedia.org/wiki/Integrated_circuit
http://en.wikipedia.org/wiki/Ni1000

The point of the analogy was:
Does it look like the real thing? Yes.
Is it the real thing? Far from it.

Re:Used to think it was a scam, not so sure now (1)

quax (19371) | about 9 months ago | (#45178981)

Ahem ... the central claim that their chip is a true quantum chip leveraging qubit entanglement has been demonstrated i.e. this paper [arxiv.org] .

Matthias Troyer, one of the co-authors, expressed in an email to me, that he was surprised to see this evidence, but that the chip seems indeed to perform some sort of quantum annealing.

Re:Used to think it was a scam, not so sure now (1)

Anonymous Coward | about 9 months ago | (#45179663)

FTA: "The strong correlations between the device and a simulated quantum annealer ... demonstrate that the device performs quantum annealing"

That's a great example of bad science. Good experiments, solid results, bad conclusions.

A strong correlation between a simulated quantum annealer and between D-Wave points to a device that performs simulated quantum annealing.

Re:Used to think it was a scam, not so sure now (1)

quax (19371) | about 9 months ago | (#45181053)

Sorry to blow your bubble, but you can actually look at the chip that's inside D-Wave's boxes. It doesn't have transistors, it has Josephson junctions. Tell me how you can get any calculations out of those unless you do physical annealing with them.

Re:Used to think it was a scam, not so sure now (0)

Anonymous Coward | about 9 months ago | (#45182473)

Oh, I'm sorry. I didn't know I was talking to someone with access to alien tech here.

Are you implying that the ***PROGRAMMABLE*** CPU in D-Wave has no transistors at all? What kind of bullshit is that?

Please enlighten us mere mortals on how the necessary state machine, fetch-decode-execute cycle and ALU can be implemented without transistors in an IC.

And it's not like we don't know how the thing is programmed, there are even tutorials: http://www.dwavesys.com/en/dev-tutorial-getting-started.html

Snippet: result = dot(self.subset_sum_array, w)**2+prod(1-w)

The above line is impossible to be implemented without a functional classical processor.

"Has transistors and some X qubits which are implemented in a secret way" - Sure.
"Has no transistors and works with magic" - Hell no.

Re:Used to think it was a scam, not so sure now (1)

quax (19371) | about 9 months ago | (#45185017)

Maybe you should spend some more time on the D-Wave site and actually read it?

On the page you link to under the "What you will learn" section:

How to use the D-Wave OneTM System as a co-processor to a conventional computer in a scalable way.

The D-Wave chip is a special purpose solver, it relies on a classical processor for loading and pre-processing, that is where this python code gets executed.

Anyhow, if you want to learn what's on the chip check out this section. [dwavesys.com]

Programming the D-Wave chip is nothing but initialising the spin states of the qubits, it has nothing to do with classical transistor logic. And no, it is not alien technology, although apparently pretty foreign to you.

Yet, you write like somebody who already made up his mind, and I doubt you're willing to learn anything that contradicts your preconceived notion.

Too much noise, all right (1)

islisis (589694) | about 9 months ago | (#45178367)

In the longterm of things, all proprietory systems will be just noise

There's two types of people in this world: (-1)

Anonymous Coward | about 9 months ago | (#45178467)

1. Those that pee in the shower
2. Liars

There's nothing sweeter than standing in a hot shower while you pee.
Who's with me? Ummm, I mean, who agrees?

Why (0)

koan (80826) | about 9 months ago | (#45178489)

Would anyone in their sane state want this:

"Integer factorization is believed to be computationally infeasible with an ordinary computer for large integers if they are the product of few prime numbers (e.g., products of two 300-digit primes).[13] By comparison, a quantum computer could efficiently solve this problem using Shor's algorithm to find its factors. This ability would allow a quantum computer to decrypt many of the cryptographic systems in use today, in the sense that there would be a polynomial time (in the number of digits of the integer) algorithm for solving the problem. In particular, most of the popular public key ciphers are based on the difficulty of factoring integers (or the related discrete logarithm problem, which can also be solved by Shor's algorithm), including forms of RSA. These are used to protect secure Web pages, encrypted email, and many other types of data. Breaking these would have significant ramifications for electronic privacy and security."

Re:Why (1)

Anonymous Coward | about 9 months ago | (#45178715)

you just went full retard

Why Develop This? (3, Insightful)

Dialecticus (1433989) | about 9 months ago | (#45178885)

Because *IF* it can be developed, someone will eventually develop it, and probably sooner rather than later. Technological advances depend less on creative genius and more on previous technological advances. It's like how radar was developed simultaneously by about a half-dozen different nations, but they were all trying to keep this supposed strategic advantage secret from one another. It's not that it was a coincidence, but rather that the time was right, and the pieces were all in place.

Isn't it better to develop a quantum computer first, so that you know to stop using vulnerable forms of cryptography? Anything else is just sticking your head in the sand. Failing to develop it yourself will not stop the other guy from doing it.

Re:Why (1)

quax (19371) | about 9 months ago | (#45178991)

Given the recent NSA revelations I think that our security in mostly illusional anyway, but if it makes you sleep better, the D-Wave machine cannot implement Shor's algorithm [wavewatching.net] .

Re:Why (1)

SuricouRaven (1897204) | about 9 months ago | (#45179641)

Eventually, there will be one that can.

I wouldn't be surprised if there already is, somewhere. The NSA is certainly reading every journal in the field, looking out for the elusive breakthrough. If they saw one being made they would likely surpress it for a few years, so they could take advantage of that window of opportunity before someone else invented it or at the very least have time to quantum-proof the US military and diplomatic communications before the tech went public. Their counterparts in other countries would doubtless have the same plan.

If someone has invented a true quantum computer, we'd find out eventually. But possibly not right away.

Re:Why (1)

quax (19371) | about 9 months ago | (#45180883)

The problem is mostly on the engineering side, it'll be hard to build up industrial capabilities of the scope needed for a useful universal gate based QC and conceal if from the rest of the world. It's not like coming up with a code cracking algorithm, the latter could be kept classified quite easily.

Re:Why (1)

lennier (44736) | about 9 months ago | (#45179021)

Would anyone in their sane state want this:

"This ability would allow a quantum computer to decrypt many of the cryptographic systems in use today."

Nobody sane, no, but the NSA and GCHQ would love that. While lighting a cigar under the "no smoking next to the nuclear weapons" sign in the pool of suspicious green ooze at the abandoned military experiment base codenamed Icarus 13 that was formerly the Lovecraft House for Angry Psychic Orphans built on top of a desecrated Indian burial ground.

Oh, no. (1)

PopeRatzo (965947) | about 9 months ago | (#45178567)

No way I'm gonna try one of these until they get the bugs out. Instead of a blue screen, I'll get a black hole and those Higgs bosons all over the carpet. My wife will kill me. Plus, they probably cost like over a thousand bucks.

But I bet GTA V runs like a banshee on it. No screen tearing, but possibly tearing in the fabric of space and time. As soon as Tiger Direct starts selling them, I'm in for one, but you best believe I'm gonna be wearing my lead codpiece when I sit in front of that thing.

Re:Oh, no. (1)

SuricouRaven (1897204) | about 9 months ago | (#45179647)

Never mind GTA - we might finally get to see what Crysis is like on full settings.

Question: How Quantum Is It? (5, Funny)

Dialecticus (1433989) | about 9 months ago | (#45178819)

Answer: It's *SO* quantum that even the issue of whether or not it's quantum exists in a superposition of states!

Re:Question: How Quantum Is It? (0)

Anonymous Coward | about 9 months ago | (#45179381)

Interesting, maybe this will happen with all quantum computing devices made in the future.

Maybe it is part of the macro quantum effect involved with a quantum computer.

Re:Question: How Quantum Is It? (0)

Anonymous Coward | about 9 months ago | (#45180567)

I let you work this out... There are no cats in the box!

When I recently sat down with D-Wave's CTO ... (3, Informative)

quax (19371) | about 9 months ago | (#45178861)

... I got the impression that he is not overtly concerned about this ongoing controversy [wavewatching.net] , although he did mention he prepared another paper to demonstrate entanglement on the chip.

But his focus is clearly on tackling hard tasks with immediate applicability (for instance in deep learning).

 

Re:When I recently sat down with D-Wave's CTO ... (-1)

Anonymous Coward | about 9 months ago | (#45179147)

Given the dozen or so posts you've made stridently defending DWave in a thread with only ~50 posts total, I'm curious: Did you "sit down with D-Wave's CTO" when you were interviewing for a position as a paid shill?

Re:When I recently sat down with D-Wave's CTO ... (1)

Anonymous Coward | about 9 months ago | (#45180663)

Good con artists are incredibly charming and charismatic. I'm not saying that this is a fraud, because I don't know, but this whole business with D-Wave reminds me too much of the movie Primer to feel comfortable. Clever engineers with a hidden agenda. There is something important that they are not telling us. Just a feeling. For all I know the secret is that they are trying to get rich by building a quantum bitcoin miner that can search the entire hash space in under a minute.

Re:When I recently sat down with D-Wave's CTO ... (1)

quax (19371) | about 9 months ago | (#45181007)

Yes, the quantum bitcoin miner thought occurred to me too :-)

There are good reasons people were suspicious of D-Wave, the way they first made a splash and overpromised delivery pushed all the right buttons. [wavewatching.net]

But to hang on to this stance after the amount of scrutiny that the D-Wave machine received is about as rational a climate change denial.

It's one thing to argue that they have not proven a quantum speed-up, but they clearly build an quantum annealing device that you can use to perform calculations.

olds (0)

Anonymous Coward | about 9 months ago | (#45179617)

This is old news.
Check the preprint dates, it says May.

what is the meaning of everything? (1)

aleator (869538) | about 9 months ago | (#45181945)

just ask such questions - but be prepared for 42 :)
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