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Why does any reasonable function need to exclude D-Wave by default? Aren't they the only company with an actual, publicly-accessible, realtime production system

Why does any reasonable function need to exclude D-Wave by default? Aren't they the only company with an actual, publicly-accessible, realtime production system you can use? I know it's not gate model, but it does compute using quantum effects, and so any reasonable model of performance has to include for this sort of system. IIRC D-Wave doesn't like single digit performance indicators, so they're aligned with Aaronson on this for once.

fsh 7y ago
There is no indication (not even from the theory side) that the D-Wave approach can achieve any speed-up over a classical computer. This is one of the reasons why Aaronson and many others in the field are not taking them seriously. Sure, they will gladly sell you a system, but the whole architecture will most likely never be useful for anything.
- correlaterdude 7y ago
  > There is no indication (not even from the theory side) that the D-Wave approach can achieve any speed-up over a classical computer. You're wrong about the theory side of things[1, 2], by the way. The discussion around adiabatic quantum computing is weirdly politicized. It's true that D-Wave's computer isn't a universal quantum annealer; but in theory such a thing is equivalent to a gate-model computer. [1] https://arxiv.org/pdf/1611.04471.pdf https://arxiv.org/pdf/1611.04471.pdf [2] https://iopscience.iop.org/article/10.1088/0256-307X/35/11/110303 https://iopscience.iop.org/article/10.1088/0256-307X/35/11/1...
  - krastanov 7y ago
    An adiabatic quantum computer is equivalent to the gate model. D-Wave do not have an adiabatic quantum computer, so there is indeed no reason, even theoretical, to believe their hardware provides computational advantage. The word "quantum annealer" is just a confusing term used differently by everyone, occasionally meaning "adiabatic quantum computer" and occasionally meaning what D-Wave have.
- core-questions 7y ago
  You sound very confident of that, but the fact that investors and developers keep moving to the platform shows that there's a good chance you're wrong. From what I can tell, the new hybrid architecture that D-Wave rolled out recently can handle way bigger optimization problems than before, and slice and dice them to fit on the still-fairly-small quantum chip. As long as optimization problems are important (and they seem to increasingly be so), something which can find lower energy states (better solutions) in a shorter time is indeed an advantage. I for one find it refreshing that they're not always blowing smoke about supremacy the way Google is - instead, they keep pushing forward actual results, like this one published in Nature: https://www.nature.com/articles/s41586-018-0410-x https://www.nature.com/articles/s41586-018-0410-x about some spinglass thing I don't understand, but it seems like it's something ideally suited for what they're building.
  - s1dev 7y ago
    It remains to be demonstrated that D-Wave has an asymptotic advantage over classical optimization algorithms. Even synthetic spin glass benchmarks specifically designed to give the DW an advantage show no advantage. Furthermore, real optimization problems have high connectivity, high weight cost function terms, and require higher precision than available. The first two will require an unacceptable overhead for fixed topology solvers. DW is not useful for real world optimization problems. Google on the other hand has actually done something a classical computer can not do
    - core-questions 7y ago
      > Furthermore, real optimization problems have high connectivity, high weight cost function terms, and require higher precision than available. Have you seen their hybrid system they just released? https://www.zdnet.com/article/this-cloud-service-lets-you-use-quantum-and-classical-computing-together-to-solve-big-problems/ https://www.zdnet.com/article/this-cloud-service-lets-you-us... Looks like it's a strong contender for people who have bigger, higher-connectivity problems that want to get ready for when the quantum processors are bigger.
      - 7y ago
kragen 7y ago
Intel, AMD, and NVIDIA also have actual, publicly-accessible, realtime production systems you can use, which also compute using quantum effects. But they don't have stable qubits and so they can't run Shor's algorithm. So D-Wave's machines are similar to AMD's and NVIDIA's, and different from quantum computers, in every relevant metric that distinguishes classical computers from quantum computers. (You don't think transistors use quantum effects? Then what's Boltzmann's constant doing in the Ebers–Moll equation?)
- core-questions 7y ago
  > But they don't have stable qubits and so they can't run Shor's algorithm. So D-Wave's machines are similar to AMD's and NVIDIA's I don't see what's "unstable" about a D-Wave qubit; it has an input bias and it has biases about the qubits it is connected to, which you can tune, and quantum coherence is held for long enough for there to provably be tunnelling effects involved in the process of settling down to a ground state. I think there's a massive lack of understanding about quantum computing that includes a huge bias against these quantum annealers, and it's baffling to me - why wouldn't someone want to see this process work? Certainly their early customers and developers see something there that you might not. Everyone's obsessed about Shor's algorithm, but it's not the most interesting thing in the world, is it? I mean, do you really want all current encryption to be rendered worthless by whoever owns it? I'm happier to see things go in the direction of solving optimization problems for traffic flow and scheduling instead of military uses, for once.
  - kragen 7y ago
    I don't mean D-Wave's devices are bad. They're just not quantum computers. They might be a better computational architecture than the mainstream ones for something (although, as I understand it, the jury is still out on that). But they can't run the quantum computation algorithms we've developed over the last 35 years, so they aren't "quantum computers" as we've been using the term for 35 years, and they won't have the effects on, for example, cryptography and our understanding of physics, that we've been predicting that "quantum computers" will have. They can't evaluate quantum circuits, they can't solve problems in BQP in polynomial time with the BQP error bound, and the whole simulation question applicable to quantum computers is inapplicable to them. These statements are not errors of reasoning attributable to some bias I might have against quantum annealers; they're just true. Calling them "quantum computers" is therefore unhelpful; it is guaranteed to cause people to draw incorrect inferences. It's like describing a slide rule, an op-amp integrator, or a harmonic analyzer as a "computer", except that that was common usage at one time. "Quantum annealers" is fine. Now, while my comment isn't motivated by any animus against the devices, which indeed might turn out to be useful, I do bear a grudge against the company D-Wave. Specifically, I think they're billing their devices as "quantum computers" precisely because they want people to draw incorrect inferences about them. That is, by using that term, they're intentionally misleading people into thinking their product can do things it can't, in order to get press and investment money. That's a very bad thing to do, and they are bad people. You ask, "I mean, do you really want all current encryption to be rendered worthless by whoever owns it?" There is a substantial field of "postquantum cryptography", with conferences going back 14 years, that will not be demolished by quantum computers. In particular, SHA-256, AES-256, and things based on them will be fine, and even a lot of cryptographic work from the 1970s will be fine if it uses those modern primitives. There are a number of public-key cryptosystems that should also work, but in most cases, we don't yet have the level of confidence in those that we have in the more conservative designs I mentioned above. The exception is Merkle signatures, which have their own disadvantages. I have a second, more disturbing objection to your query about what "I want": you seem to be presupposing that my beliefs about D-Wave, and perhaps everyone's beliefs about everything all the time, are determined exclusively by wishful thinking. Consider, perhaps, that this may not be the case — some of the time people may have beliefs that they would prefer to be incorrect, based on, for example, evidence or careful reasoning. In fact, I would assure you that this is true, but certainly you could dismiss that as more wishful thinking on my part. While it's convenient to attribute people disagreeing with you to "a massive lack of understanding" or to wishful thinking, often it turns out that they instead disagree with you because they know things you don't. Under those circumstances, it can sometimes be more useful to avoid insulting them.
ggm 7y ago
It's precisely because the D-Wave and other like systems are not yet able to run Shor, I proposed "algorithm like shor". And its shorthand for "computation which demands more than just inference across the statistical sum of the semi-incoherent output states you see in a sea of things" which as I understand it, is what D-Wave does: it emits all the things, and you do work to find the answer (which usually you knew a-priori btw, another gap in my feelings on QC right now: the worked examples always include for-knowledge of the "right" answer to help decode it from the output states of the QC under consideration) BTW if I mis-characterize either the state of QC or D-Wave I apologize. I am not in the field. I get this view, from what little I can understand.
- core-questions 7y ago
  Yeah, I'm just a sysadmin so I don't really get it either, but I've been following them for a while out of a layman's interest. My understanding is that there was already a body of work in the direction of optimization problems formulated as "Ising Hamiltonians", which is some mathematical construct that it's hard to calculate the lowest-energy configuration for; D-Wave took the most practical route to yielding actual working qubits possible, and can solve those Ising problems on there. What we're forced to imagine is a future 5-10 years from now when they have 10k or 20k qubits, or they're all way more connected together, or something like that; there comes a point at which it will truly be very useful for big problems, and so the speculative player who wants to profit off of this would spend their time trying to actually make working models of something useful in reality which uses such an optimization solver as an engine underneath.

fsh 7y ago

There is no indication (not even from the theory side) that the D-Wave approach can achieve any speed-up over a classical computer. This is one of the reasons why Aaronson and many others in the field are not taking them seriously. Sure, they will gladly sell you a system, but the whole architecture will most likely never be useful for anything.

correlaterdude 7y ago
> There is no indication (not even from the theory side) that the D-Wave approach can achieve any speed-up over a classical computer. You're wrong about the theory side of things[1, 2], by the way. The discussion around adiabatic quantum computing is weirdly politicized. It's true that D-Wave's computer isn't a universal quantum annealer; but in theory such a thing is equivalent to a gate-model computer. [1] https://arxiv.org/pdf/1611.04471.pdf https://arxiv.org/pdf/1611.04471.pdf [2] https://iopscience.iop.org/article/10.1088/0256-307X/35/11/110303 https://iopscience.iop.org/article/10.1088/0256-307X/35/11/1...
- krastanov 7y ago
  An adiabatic quantum computer is equivalent to the gate model. D-Wave do not have an adiabatic quantum computer, so there is indeed no reason, even theoretical, to believe their hardware provides computational advantage. The word "quantum annealer" is just a confusing term used differently by everyone, occasionally meaning "adiabatic quantum computer" and occasionally meaning what D-Wave have.
core-questions 7y ago
You sound very confident of that, but the fact that investors and developers keep moving to the platform shows that there's a good chance you're wrong. From what I can tell, the new hybrid architecture that D-Wave rolled out recently can handle way bigger optimization problems than before, and slice and dice them to fit on the still-fairly-small quantum chip. As long as optimization problems are important (and they seem to increasingly be so), something which can find lower energy states (better solutions) in a shorter time is indeed an advantage. I for one find it refreshing that they're not always blowing smoke about supremacy the way Google is - instead, they keep pushing forward actual results, like this one published in Nature: https://www.nature.com/articles/s41586-018-0410-x https://www.nature.com/articles/s41586-018-0410-x about some spinglass thing I don't understand, but it seems like it's something ideally suited for what they're building.
- s1dev 7y ago
  It remains to be demonstrated that D-Wave has an asymptotic advantage over classical optimization algorithms. Even synthetic spin glass benchmarks specifically designed to give the DW an advantage show no advantage. Furthermore, real optimization problems have high connectivity, high weight cost function terms, and require higher precision than available. The first two will require an unacceptable overhead for fixed topology solvers. DW is not useful for real world optimization problems. Google on the other hand has actually done something a classical computer can not do
  - core-questions 7y ago
    > Furthermore, real optimization problems have high connectivity, high weight cost function terms, and require higher precision than available. Have you seen their hybrid system they just released? https://www.zdnet.com/article/this-cloud-service-lets-you-use-quantum-and-classical-computing-together-to-solve-big-problems/ https://www.zdnet.com/article/this-cloud-service-lets-you-us... Looks like it's a strong contender for people who have bigger, higher-connectivity problems that want to get ready for when the quantum processors are bigger.
    - 7y ago

kragen 7y ago

Intel, AMD, and NVIDIA also have actual, publicly-accessible, realtime production systems you can use, which also compute using quantum effects. But they don't have stable qubits and so they can't run Shor's algorithm. So D-Wave's machines are similar to AMD's and NVIDIA's, and different from quantum computers, in every relevant metric that distinguishes classical computers from quantum computers. (You don't think transistors use quantum effects? Then what's Boltzmann's constant doing in the Ebers–Moll equation?)

core-questions 7y ago
> But they don't have stable qubits and so they can't run Shor's algorithm. So D-Wave's machines are similar to AMD's and NVIDIA's I don't see what's "unstable" about a D-Wave qubit; it has an input bias and it has biases about the qubits it is connected to, which you can tune, and quantum coherence is held for long enough for there to provably be tunnelling effects involved in the process of settling down to a ground state. I think there's a massive lack of understanding about quantum computing that includes a huge bias against these quantum annealers, and it's baffling to me - why wouldn't someone want to see this process work? Certainly their early customers and developers see something there that you might not. Everyone's obsessed about Shor's algorithm, but it's not the most interesting thing in the world, is it? I mean, do you really want all current encryption to be rendered worthless by whoever owns it? I'm happier to see things go in the direction of solving optimization problems for traffic flow and scheduling instead of military uses, for once.
- kragen 7y ago
  I don't mean D-Wave's devices are bad. They're just not quantum computers. They might be a better computational architecture than the mainstream ones for something (although, as I understand it, the jury is still out on that). But they can't run the quantum computation algorithms we've developed over the last 35 years, so they aren't "quantum computers" as we've been using the term for 35 years, and they won't have the effects on, for example, cryptography and our understanding of physics, that we've been predicting that "quantum computers" will have. They can't evaluate quantum circuits, they can't solve problems in BQP in polynomial time with the BQP error bound, and the whole simulation question applicable to quantum computers is inapplicable to them. These statements are not errors of reasoning attributable to some bias I might have against quantum annealers; they're just true. Calling them "quantum computers" is therefore unhelpful; it is guaranteed to cause people to draw incorrect inferences. It's like describing a slide rule, an op-amp integrator, or a harmonic analyzer as a "computer", except that that was common usage at one time. "Quantum annealers" is fine. Now, while my comment isn't motivated by any animus against the devices, which indeed might turn out to be useful, I do bear a grudge against the company D-Wave. Specifically, I think they're billing their devices as "quantum computers" precisely because they want people to draw incorrect inferences about them. That is, by using that term, they're intentionally misleading people into thinking their product can do things it can't, in order to get press and investment money. That's a very bad thing to do, and they are bad people. You ask, "I mean, do you really want all current encryption to be rendered worthless by whoever owns it?" There is a substantial field of "postquantum cryptography", with conferences going back 14 years, that will not be demolished by quantum computers. In particular, SHA-256, AES-256, and things based on them will be fine, and even a lot of cryptographic work from the 1970s will be fine if it uses those modern primitives. There are a number of public-key cryptosystems that should also work, but in most cases, we don't yet have the level of confidence in those that we have in the more conservative designs I mentioned above. The exception is Merkle signatures, which have their own disadvantages. I have a second, more disturbing objection to your query about what "I want": you seem to be presupposing that my beliefs about D-Wave, and perhaps everyone's beliefs about everything all the time, are determined exclusively by wishful thinking. Consider, perhaps, that this may not be the case — some of the time people may have beliefs that they would prefer to be incorrect, based on, for example, evidence or careful reasoning. In fact, I would assure you that this is true, but certainly you could dismiss that as more wishful thinking on my part. While it's convenient to attribute people disagreeing with you to "a massive lack of understanding" or to wishful thinking, often it turns out that they instead disagree with you because they know things you don't. Under those circumstances, it can sometimes be more useful to avoid insulting them.

ggm 7y ago

It's precisely because the D-Wave and other like systems are not yet able to run Shor, I proposed "algorithm like shor". And its shorthand for "computation which demands more than just inference across the statistical sum of the semi-incoherent output states you see in a sea of things" which as I understand it, is what D-Wave does: it emits all the things, and you do work to find the answer (which usually you knew a-priori btw, another gap in my feelings on QC right now: the worked examples always include for-knowledge of the "right" answer to help decode it from the output states of the QC under consideration) BTW if I mis-characterize either the state of QC or D-Wave I apologize. I am not in the field. I get this view, from what little I can understand.

core-questions 7y ago
Yeah, I'm just a sysadmin so I don't really get it either, but I've been following them for a while out of a layman's interest. My understanding is that there was already a body of work in the direction of optimization problems formulated as "Ising Hamiltonians", which is some mathematical construct that it's hard to calculate the lowest-energy configuration for; D-Wave took the most practical route to yielding actual working qubits possible, and can solve those Ising problems on there. What we're forced to imagine is a future 5-10 years from now when they have 10k or 20k qubits, or they're all way more connected together, or something like that; there comes a point at which it will truly be very useful for big problems, and so the speculative player who wants to profit off of this would spend their time trying to actually make working models of something useful in reality which uses such an optimization solver as an engine underneath.