Inside is also a link to the whitepaper on how to program the DWave, which has a lot more detail on "ok, but what does that mean I can do with it, and how?". More or less, you need to map your problem space to the functioning of the DWave (a series of weights), and then you need to map the answer space of the DWave (out-state of each qubit) back to your problem space. The DWave doesn't actually return a canonical answer, but rather a bundle of statistics for each qubit, from which you then determine your answer (say, by taking the average).
Some things to remember, aside from the debate about whether it's actually a QC and actually uses entanglement to produce answers:
1) All 2k qubits are NOT entangled with each other
The qubits are grouped into cells, and the cells have a coupling between them, but each qubit does not (directly) interact with all other qubits. This is a large part of why it's not a "general" quantum computer; it's more like an ASIC.
2) You program in "similarity" and "dissimilarity" to neighboring qubits, and an initial weighting.
Each qubit in the dwave has some programmed possibility of being 1 or 0, and of being the same or different from each neighbor. "Running" the calculation more or less applies all these weights, and then you look at the resulting state.
3) The "answer" is actually the statistics on multiple measurements.
After programming the weights, you run the machine, and get out an answer. You do this 50, 100, whatever, times, and now you have statistics on the state of each qubit. From this you determine your answer; AFAIK, usually you just take the average.
The main interconnect fabric of FPGA typically consists of enough wires and programmable switches that you don't have to care that much that their topology is fixed.
In the D-Wave case it looks like the topology of coupling between cells is completely fixed.
Does anyone know if anyone actually uses these D-Wave systems in production for practical applications? Are there any applications for which these are already faster/cheaper than traditonal computers?
Lockheed has one in Fort Worth. Best I can tell they want to run aerodynamics simulations on it.
I actually interviewed for a field engineer position with D-Wave embedded at Lockheed in Fort Worth. Apparently I wasn't smart enough for them because they went radio silent after the phone interview.
> Best I can tell they want to run aerodynamics simulations on it.
I'm a CFD guy and I have absolutely no clue how anyone expects to get any aerodynamics simulation results out of that with anything resembling usefulness.
Really, even a super-simple 2D wing profile simulation that you can run in milliseconds even in javascript will require data storage that's absolutely massive compared to 2000 qubits.
Quantum computers have several algorithms for various applications, such ashort shors for factorization. Not aware of any algos for CFD.
Perhaps a rarefied gas dynamics, bolts man distribution sort of application could be created? At least in some cases quantum mechanical effects are significant...
They want to run anything on it, not just aerodynamics simulations. All the various sites across the US are encouraged to think of ways to use it and submit jobs remotely, whether its for aero, radar, missiles, etc
Yeah, but I got the impression that the aero sims were viewed as the low-hanging fruit to demonstrate that the computer could actually do things better than traditional machines.
Are you sure it's actually at Fort Worth? I know that they bought the one that's that's at USC's Information Sciences Institute, but I hadn't heard that the bought another one. As far as I know they've just paid for that one to be upgraded a couple times.
The one at USC definitely isn't being used for anything past the research level.
Nope, D-Wave is still sponsoring research to find problems where the D-Wave beats consumer PCs (I think the iPad Pro might actually be competitive with it now).
It basically performs the same function as traditional combinatoric optimization algorithms, e.g. simulated annealing and evolutionary optimization, but it does a much much much better job at it since it can test the superposition of the entire search space instead of picking at points here and there.
This is not true. It can not test the superposition of the entire search space - this would require an actual quantum computer. (Or maybe I misunderstood your ELI5 explanation, in which case I am sorry)
I'm not sure where you're getting your information: everyone in this thread seems to be parroting the same popsci headline that it's not a "real" quantum computer, but that completely misses the point. Regardless of whether or not it's a general purpose computing machine with programmable logic, it can still perform mathematical optimization of an objective function over a superposition of bits. Saying that it's not quantum because it's not general purpose is a complete distortion of the facts.
Here is my claim in precise terms: superposition of all combinatorial states is a very non-classical state. Preparing such a state is still an active area of research, and nobody has yet made one in a usable fashion. The D-wave device does not have a superposition of states, rather it is tracking a single classical state as far as I know. No need for harsh language in your response.
Edit: removed an incorrect remark about entanglement.
>The D-wave device does not have a superposition of states, rather it is tracking a single classical state
I'm going to need a citation on that.
Even if only some small fraction of the qubits in the 2^2000 search space are fully entangled, that's still a massive improvement over the current state of the art using conventional computers because of how absolutely huge the space is.
Not if the entanglement is partitioned into very small groups of qubits. That's the only thing we have even circumstantial evidence of, and it doesn't appear to gain us much over classical computers. This is especially bad for the "it'll be better with more qubits" hypothesis D-Wave is chasing, since everything we know about quantum control suggests that if you can't solve this problem with a 1000-qubit system, doing it with a 2000-qubit system is going to be even harder.
We're still waiting for one problem, no matter how arbitrary, where the D-Wave beats basic consumer computers, let alone a few million dollars worth of computing power. And if D-Wave (or anyone else) had found one for their 2000-qubit computer, it would be in this press release. So no, any gain in performance form the D-Wave hardware is still in the "theoretical but without any theoretical backing" stage.
>We're still waiting for one problem, no matter how arbitrary, where the D-Wave beats basic consumer computers
This is like saying that NASA has never gone to space, because there is not ONE thing they have EVER done in space, no matter how arbitrary, (including going to the moon) that I care about more than literature.
Let's look at the parts of my analogy:
NASA has not gone to space BECAUSE it is not better than something irrelevant.
DWAVE does not have a quantum computer BECAUSE it is not better than something irrelevant.
What on Earth do classical computers have to do with whether DWAVE is using quantum effects?
This is very irrelevant.
I can't believe so many people use this to "prove" that it's not a quantum computer. This is a complete and utter non sequitur.
This is very basic logic. It's like saying that until the minute a machine beat Kasparov at chess, computers couldn't play chess.
In a very narrow sense of cheating, sure, a computer could fake playing chess if a person is hidden and playing for the computer. Maybe the comouter isn't even powered on. Likewise, in a narrow sense a classical computer could be hidden in the DWAVE's cabinet and producing the output with a python script. Maybe the DWAVE isn't even powered on. (and has a cheater inside, a macbook.)
But short of this scenario it is a completely inappropriate point to make. It doesn't say anything about how dwave works.
-> Are you accusing them of not even powering it on and hiding a macbook in the case, which produces all its results? (if not, how is your contention different.)
> I can't believe so many people use this to "prove" that it's not a quantum computer. This is a complete and utter non sequitur.
That's not why I'm saying it's probably not a quantum computer. It's not a quantum computer because in depth analysis of its behavior has consistently shown that above the ~20 qubit scale it's better modeled by a classical explanation than a quantum one. We only really have evidence of entanglement at the 8 qubit level[1] so far.
The fact that the processing power is abysmal just makes the hype even more ridiculous. The point of that fact is that it's not like the EmDrive, where it's doing something we can't yet explain under the assumption that nothing interesting is going on. If it weren't for the fact we've looked inside, it could be running a basic Intel CPU for all we know. There's no smoke at any level, so it's nonsensical to give D-Wave a pass and think they've got some fire.
But when you raise the bar to "better than a desktop PC" it is like going from "well the burden is on chess computers to prove their machine really plays chess" to "the burden is on chess computers to prove they're better than humans (and it's not real until they do.)". That is too high a bar.
My only objection is on this suggestion - that they have to find something it's already better at than a desktop PC (with literally billions of transistors).
But scaling laws should predict that you should need many, many more transistors than qubits to beat a gate quantum computer. For an adiabatic quantum computer something similar should hold.
Whether or not you agree that D-wave has proper superposition and is properly performing quantum annealing your original statement was different from this one. You wrote: "it can test the superposition of the entire search space instead of picking at points here and there."
That's similar to common misconceptions on how quantum computers work which might attract some of your downvotes, but more importantly you're also misrepresenting why quantum annealing is faster than thermal annealing.
I'm parroting the information I've gotten from hearing people who work with the D-Wave describe their research, reading their papers, and friends who work in the area. So no, I didn't just read a popsci headline that tickled my contrarian bone.
A non-general quantum computer could still be considered to be a "quantum computer" in the way that physicists use the term. We'd definitely consider a computer that could "only" run Shor's algorithm to be one, so that's not a reason to write off the D-Wave.
If you mean in a "quantum computer" sense, no. They're slower than classical alternatives for sure, and significant entanglement has yet to be demonstrated. Even theoretically, D-Wave has yet to produce any reasons to believe the mechanism of operation is quantum in any significant way.
Remember your CPU requires quantum mechanics to explain its operation (above and beyond "that's why the atoms don't implode"), so "it does quantum things" does not a quantum computer make.
Yes, I meant it as in, "Processes qubits with entangled ensembles of photons". Thanks for the answer, it's what I remembered from the last time I'd read about them, but that was a while ago.
There were a couple papers a year ago showing pretty convincingly that yes there is some entanglement between some of its qubits. But from what I've seen there's zero evidence that they've done anything that would be hard for a classical computer. All signs thus far point to snake oil, but with a genuinely great team. They'll probably do something interesting 5 years from now and then Geordie will point back at all the naysayers and say "see I told you so!!"
Their only innovation seems to be "more qubits that haven't even be demonstrated to be qubits", so I'm a bit sceptical that their future endeavors will do much. Either the team or their management is insisting they ignore everything we know about adiabatic quantum computing despite having not found a hint of contradicting evidence.
> D-Wave’s quantum system runs a quantum annealing algorithm to find the lowest points in a virtual energy landscape representing a computational problem to be solved.
In statistics and machine learning, this is great for finding optima in cost functions.
You are right, what I actually meant is "great once quantum computing becomes a commercially viable route" :-)
Regarding the second line of your comment: I don't have comprehensive knowledge about the possible alternatives, could you direct me towards some sources?
"In the current model of the D-Wave chip, there are 1,000 or so qubits [quantum bits], but they’re organized into clusters of eight qubits each."
"what the Google paper finds is that Selby’s algorithm, which runs on a classical computer, totally outperforms the D-Wave machine on all the instances they tested."
Now they've just made a machine of twice as much qubits but is there any performance advantage compared to the code run on the classical computer?
Would be good to know what "up to" means in "up to 1000 times faster". By any chance, isn't it the same "up to" as in "you can win up to 100 million dollars in a lottery"?
Now this is starting to get interesting. 2000 qubits is where it starts being applicable to meaningful real-world combinatoric optimization problems. I would kill to have access to one of these machines for my research...
The "beef" is that, whatever your research is, you already have access to better, faster, cheaper tools. Unless your area of research is "D-Wave machines", I suppose! Otherwise the computer you typed this comment on is unquestionably better for your area of research than a D-wave machine, because it 1) can solve a thousand times more types of problems and 2) is much faster at the tiny set of problems D-wave machines can address.
This is interesting research in an interesting area; it's certainly not a scam. But it's also not what you seem to imagine, doesn't work like you're assuming, isn't useful for what you hope, and shows no signs of being headed in that direction. Yes, 2000 entangled qubits that could be used to solve arbitrary problems would be amazing, but D-Wave isn't making that, isn't claiming to be making that, and doesn't seem to be working on a way to make that.
I don't think you should be downvoted, but if you have a hard-on for spending a lot of money on a helium cooled computer for these problems, you'd be better off retrofitting a mid-level PC with helium cooling and overclocking it. Probably by an order of magnitude.
The search for good problems for the D-Wave (irrespective of whether anyone cares about their answers) is still on.
A search space that's 2^2000 big when each fitness function evaluation takes a few seconds is intractable on a conventional computer. The relative performance gain is exponential the more qubits you add, which is why this is the first interesting quantum computer (or quantum optimizer if you're being picky).
Yes, but you don't get to just input any optimization problem into the dwave. The problem is that the specific kind of optimization that the dwave can do (even ignoring the fact that the output doesn't correspond directly with a solution) hasn't been found to map to any problems classical computers are actually bad at.
If you really think the problems you work on are that novel and up the D-Wave's alley, I suggest you email one of the academic teams looking for problems that the D-Wave is good at. They've yet to find any.
Could a D-Wave be used to perform Shor's algorithm? I remember reading a long time ago that In-Q-Tel and an unnamed 3-letter agency had invested in D-Wave
I'm surprised that none of the quantum computing companies I've seen are talking about moving from copper wires to optical wires. It feels a bit like putting a Ferrari engine into a VW Bug.
Because of thermal noise these things are very cold. At that point the wires are superconducting so you need not worry about that type of losses. None of the advantages of optical processing translate from the classical regime to the quantum.
You're suggesting putting a Ferrari chassis around a 6hp outboard motor. A quantum computer is not a fast computer, it is a different kind of computer.
I mean, the wires are only relevant to the control of the machinery (not the actual computation) and these aren't photonic quantum computers anyway. What's the point of putting a bunch of optical fibers with electronic emitters and receivers on both sides?
Has anyone shown that this isn't simply a hollow black box with a slightly outdated conventional computer inside? Based on performance metrics alone, this would seem likely.
I get the feeling (and its more likely) that D-Wave has solved the P=NP question in the affirmative and have polynomial equations to solve NP problems. As far as I know, getting qubits to stay coherent is a difficult, unsolved problem as the number of qubits increases. Of the QC research that I have read about they are using a handful of qubits to factor really small numbers like 15. Nobody, at least publicly, is even working with 100's of qubits let alone 2K.
To avoid public disclosure that P=NP (and losing out on any way to monetize their discovery) they are hiding their work behind a "quantum computer" which is a vague and sophisticated enough cover (nobody really understands quantum physics) to dupe some customers while the P equations run in ring-zero of a normal CPU. What would be interesting is to read the sales contracts for these machines. My guess is they are written in such a way that D-Wave makes no promises or guarantee that they are actually using qubits to solve customer's problems, just that they promise to solve customer's NP problems with D-Wave computers, regardless of the method. Moreover, I'd bet that the language states that the machines sold are "equivalent" to a 2000 qubit computer and not necessarily a 2KQbit processors. In this way D-wave is off the legal hook if/when the NP=P solution is revealed by D-Wave or others. My second guess is that these sales contracts are protected by NDA's.
Theres a lot of reasons this isn't possible, let alone probable.
1. The "algorithms" are input by the users, not dwave. Moreover, you don't even have a way to input an NP-complete problem. You can only input the setup for a very specific type of optimization problem.
2. You're not comparing like with like. Even Dwave doesn't claim to have a general, gate based quantum computer like the sub-100 gate quantum computers you're talking about. The also don't claim coherent entanglement of all 2k qubits; they've still failed to convince anybody more than a handful get entangled together coherently during the operation of the device.
3. The dwave has yet to beat a laptop at any problem, let alone the NP-complete problems of their customers. The only people who buy D-Wave systems are those doing pure research.
4. The sales contracts aren't protected by NDAs. I've talked to people who work on Lockheed's D-Wave (at USC), and all their investigations are freely available on the Arxiv.
Okay, so where is the beef? u/krastanov blasted me too but the question remains, what are they doing? How can they sell single computer if your point #3 is true? I would think that researchers must be smart enough to sniff out a scam so I have to think DW must offering some thing new, different or superior to standard CPUs or processing -- even if primitive and expensive. Moreover, if your point #2 is true then how can they claim to be offering a 2K qbit computer? It makes no sense as long as words have real meaning.
Look at it from the perspective of the people who have bought their computers (e.g. Google, Lockheed). Suppose there's any remote chance this is the first step towards scalable quantum computing. If that's the case, getting your researchers in on the ground floor could lead to what would likely be one of the most valuable pieces of IP since the transistor. D-Wave's patents might not cover it since their patents describe devices that don't really appear to work, and you're big enough to buy them if they do. Governments, every physical science, and plenty of firms big data would be dying to get their hands on your devices.
Now look at the cost of the D-Wave. A few million dollars, compared to the trillions you could make just in licensing fees if it pans out and you were the ones to crack the code. Considering how deep these companies' pockets are, wouldn't you take that bet? I would, and I side with the evaluations of some of the biggest D-Wave skeptics in academia.
Fine. I concede your points (except the part about being "dense" with errors).
The essence of my argument still stands and you can easily recast my argument, if you cared to think about it, in a form that is consistent with your vastly superior knowledge of QM, QC, P=NP, etc. If your point #1 is true then how can DW sell a single computer? That makes no sense on the face of it. Do you propose that their customers are buying them in an act of charity or that they are too stupid to notice its a scam? Don't forget these machines sell for millions of Thalers. Clearly, to make a sale DW must have demonstrated some thing superior to the Intel or standard CPU in solving some kind of problem. My guesses at "thing" and "kind" are wrong but my argument stands.
The gist of the issue for me is that DW is claiming to cohere 2000 qbits when the "state of the art" is a handful, at best. So I say, let's see sales contract and check out what are they really selling. That point stands despite your objections too.
A big part of how they sell those machines is indeed PR, and this annoys a lot of quantum information researchers. My guess is that those who buy their machines are just trying to cover all their bases. I do have to concede that their hardware is an interesting exercise in engineering, but nothing more.
Quantum computers do not make NP-hard problems significantly easier to solve than on classical computers.
They're better at prime factorization, but in a way that's well understood (quantum Fourier transform) and possible to simulate on classical computers.
Inside is also a link to the whitepaper on how to program the DWave, which has a lot more detail on "ok, but what does that mean I can do with it, and how?". More or less, you need to map your problem space to the functioning of the DWave (a series of weights), and then you need to map the answer space of the DWave (out-state of each qubit) back to your problem space. The DWave doesn't actually return a canonical answer, but rather a bundle of statistics for each qubit, from which you then determine your answer (say, by taking the average).
Some things to remember, aside from the debate about whether it's actually a QC and actually uses entanglement to produce answers:
1) All 2k qubits are NOT entangled with each other The qubits are grouped into cells, and the cells have a coupling between them, but each qubit does not (directly) interact with all other qubits. This is a large part of why it's not a "general" quantum computer; it's more like an ASIC.
2) You program in "similarity" and "dissimilarity" to neighboring qubits, and an initial weighting. Each qubit in the dwave has some programmed possibility of being 1 or 0, and of being the same or different from each neighbor. "Running" the calculation more or less applies all these weights, and then you look at the resulting state.
3) The "answer" is actually the statistics on multiple measurements. After programming the weights, you run the machine, and get out an answer. You do this 50, 100, whatever, times, and now you have statistics on the state of each qubit. From this you determine your answer; AFAIK, usually you just take the average.