Who even asked these questions? I question this. All of this.
Literally people on HN have been asking many of these questions for years whenever QC is discussed.
Scott’s Supreme Quantum Supremacy FAQ
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Re: Scott’s Supreme Quantum Supremacy FAQ
#72What's e.g. China and Russia doing in this space? Or the US Gov't for that matter? I can't imagine that national governments are just waiting for Google and IBM to do the research and publish their results. Is it possible/likely that NSA or some other national equivalent is way beyond these results already?
I don't know what the NSA spends on R&D, but I have to imagine they don't have a multi-billion dollar budget for secret R&D facilities and talent. It would seem more likely they are monitoring developments in public and private research and responding opportunistically. I'm just making assumptions here, but also I don't think somebody with clearance could correct me here in public :P
I'd think the opposite. I would imagine they have orders of magnitude more to spend on crypto research than a private search engine company (which is why I asked the question originally). But really I have no idea. (If they did then why aren't there job ads etc). And you're right, probably nobody who does have an idea would be able to say.
Re: Scott’s Supreme Quantum Supremacy FAQ
#73Earlier quoted context omitted.
I was a little too fast and loose in my previous post. You are correct that we want a large [number of qubits] on a chip eventually. The chips are tiny and the fridges large enough for now (50 qubits). It's not clear to me that they can handle thousands of qubits as imagined. The cryostat will undoubtedly be able to house the chip, but the extra electronics / cables must run in there as well. With 1000 qubits and 2 c…
There is a scalability problem but due to different reasons. See my other comment in this thread for details. Classical circuitry is an issue, but not as much as you think. What happened is Martinis' group and others moved forward with a quick & dirty design which worked well for their device but can't be scaled (they basically didn't have the expertise like silicon people had). Nevertheless, it's not a fundamental p…
I agree on your other points and trust that you are more qualified to judge what the biggest obstacles are.
Do you have a paper I can look into that goes into the chip architectures in more detail (not specifically for this new device)? Otherwise I'll await the science / nature paper of this demonstration.
The classical circuit is mostly outside the cryo I assume since it's GHz's and LNAs are available. Do you know if the microwave readout signal is frequency multiplexed to reduce cables?
Re: Scott’s Supreme Quantum Supremacy FAQ
#74Earlier quoted context omitted.
You may not agree with the authors' or Aaronsons' definition of quantum supremacy, that's ok. I think his definition is very reasonable. Aaronson argues that this experiment will prove quantum computing supremacy in great length and defined it in the first entry of the FAQ as follows: > [quantum computing supremacy] term refers to the use of a quantum computer to solve some well-defined set of problems that would tak…
Yea... I’m not suggesting of course that Scott is wrong about this being an illustration of “quantum supremacy”... (Did you think I was...?) But comparing it to manned flight or the first nuclear reactor... In those two cases there was a clear path to something very useful. I’m my mind this experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ev…
> But comparing it to manned flight or the first nuclear reactor (...) this experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ever have them.
Not a lot of people directly own & operate their own airplane, let alone a nuclear reactor, and yet both have had a significant impact on modern life. As for this experiment & QC, only time will tell of course.
Re: Scott’s Supreme Quantum Supremacy FAQ
#75Earlier quoted context omitted.
It can't really be explained, we kind of accept it works like it has been in both states at once until the box was opened. Similarly, we don't really know how to explain how particles travel by both slits at once in the double-slit experiment.
Idk, it seems to me like https://www.smbc-comics.com/comic/the-talk-3 is a pretty good explanation. “A new ontological category”. What’s the problem?
satire and educational
this has been the best thing I've seen so far
Re: Scott’s Supreme Quantum Supremacy FAQ
#76Earlier quoted context omitted.
Well D-wave is evaluated on an optimization task. This Google thing isn’t even trying to solve a real problem. What says you can’t get some very hard to replicate random bits out of a D-wave?
Do you retract the claim Ising model problems are "extremely difficult" for classical computers? I replied with practical and theoretical considerations why it is not so.
I made no claim at all, I just stated an assumption that motivated my question. But you also misrepresent my assumption. My assumption was that the D-wave could sample from the solutions to “ising model-like problems” much more efficiently than a classical computer. A quick glance at your references gave me the impression they where about finding a single ground state / global minima of the hamiltonian. That’s a very different problem.
Re: Scott’s Supreme Quantum Supremacy FAQ
#77Earlier quoted context omitted.
You may not agree with the authors' or Aaronsons' definition of quantum supremacy, that's ok. I think his definition is very reasonable. Aaronson argues that this experiment will prove quantum computing supremacy in great length and defined it in the first entry of the FAQ as follows: > [quantum computing supremacy] term refers to the use of a quantum computer to solve some well-defined set of problems that would tak…
Yea... I’m not suggesting of course that Scott is wrong about this being an illustration of “quantum supremacy”... (Did you think I was...?) But comparing it to manned flight or the first nuclear reactor... In those two cases there was a clear path to something very useful. I’m my mind this experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ev…
Well I don't want to answer for him but you could make the same point with the airplane:
The first flight was 2 people in a plane that lasted very short. I could have ridden my horse more quickly over that distance! How is this a meaningful milestone?!
Well.. it demonstrates something that cannot be done on a horse (classical computer) but that can be done with a plane (quantum computer).
Is the application useful today? Probably not. But that shouldn't discourage anyone.
Re: Scott’s Supreme Quantum Supremacy FAQ
#78Earlier quoted context omitted.
Yea... I’m not suggesting of course that Scott is wrong about this being an illustration of “quantum supremacy”... (Did you think I was...?) But comparing it to manned flight or the first nuclear reactor... In those two cases there was a clear path to something very useful. I’m my mind this experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ev…
> But comparing it to manned flight or the first nuclear reactor (...) this experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ever have them. Not a lot of people directly own & operate their own airplane, let alone a nuclear reactor, and yet both have had a significant impact on modern life. As for this experiment & QC, only time will tell of…
I think you misinterpreted "we will ever have them" part. bjornsing is not talking about whether there will be personal quantum computers. It is about whether there will be useful quantum computers at all. That is still open, for example because of issues related to quantum error correction.
Re: Scott’s Supreme Quantum Supremacy FAQ
#79If it goes well, the history of quantum computing will be divided up in to three eras: the era of twisty philosophical arguments that it's working ("the molecule is simulating itself"), the era of academic arguments that it's working ("we can solve this one carefully constructed problem") and the era of practical arguments ("Amazon is selling QC time for $20/kilogate-bit, what do you mean it's not possible?"). Quantu…
What are the theoretical models for the energy cost of computing on a qubit? I'll be excited for QC when there is known way (even with some handwaving and future-tech plans) to compute a non-trivial result for a reasonable sum, such as "crack someone's private RSA key for under $10M of compute cost"
> when there is known way (even with some handwaving and future-tech plans) to compute a non-trivial result for a reasonable sum, such as "crack someone's private RSA key for under $10M of compute cost"
If you're willing to admit handwaving and future-tech plans, then you can be excited now. It's estimated that a few million physical qubits (corresponding to few thousand logical qubits) will be necessary to crack an RSA key. It's at least a decade away, maybe several, but few experts believe there are hard barriers to number of qubits or minimal cost.
Re: Scott’s Supreme Quantum Supremacy FAQ
#80Earlier quoted context omitted.
You may not agree with the authors' or Aaronsons' definition of quantum supremacy, that's ok. I think his definition is very reasonable. Aaronson argues that this experiment will prove quantum computing supremacy in great length and defined it in the first entry of the FAQ as follows: > [quantum computing supremacy] term refers to the use of a quantum computer to solve some well-defined set of problems that would tak…
Yea... I’m not suggesting of course that Scott is wrong about this being an illustration of “quantum supremacy”... (Did you think I was...?) But comparing it to manned flight or the first nuclear reactor... In those two cases there was a clear path to something very useful. I’m my mind this experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ev…
> This experiment changes very little as to how probable it is that we will soon have useful quantum computers, or even that we will ever have them.
I completely agree with this statement. This is mainly about Extended Church-Turing Thesis.