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> He said: “This is a very nice demonstration of quantum advantage. While a great achievement academically, the algorithm used does not really have real world p

> He said: “This is a very nice demonstration of quantum advantage. While a great achievement academically, the algorithm used does not really have real world practical applications, though. > “We really must get to utility quantum computing – an era where quantum computers with many thousand qubits actually begin to deliver value to society in a way that classical computers never will be able to.” This seems to be the most level headed take from the paper and an explanation why (if claims are to be believed) we haven't seen anything useful come from quantum computing yet that couldn't be done by classical computers. Maybe it still is all hype and the reason we haven't seen a useful calculation is because the only problems it can solve better than others happen to be especially contrived. I guess time will tell.

tedivm 3y ago
I don't think it's that the concepts are contrived (although the test cases certainly are), it's just that our quantum computers are really early in their development and can't do the more complicated things yet. It's like if we had calculators that took an hour to do each arithmetic operation- the fact that people wouldn't use it doesn't mean arithmetic is contrived, just that it isn't as powerful as better alternatives. As the quote mentions, we'll need "many thousand qubits" to reach the point where society itself is getting new benefits out of things. These contrived cases help figure out how to scale the whole system.
- upofadown 3y ago
  It's more like if we had calculators that could not do any arithmetic operation at all... Someone someday might figure out how to make the calculator actually calculate, but not yet.
- AbrahamParangi 3y ago
  There's a fundamental question as to whether or not it's exponentially difficult to add additional qubits. If each marginal qubit is 5% more difficult to add as the previous one the task would be essentially impossible - and even if it wasn't impossible it would turn out to basically be cheating (in that you would be doing exponential work via either the quantum computing route or the conventional route).
  - alpineidyll3 3y ago
    Note: that there is good physical reasons why the cost of QC may grow exponentially with qbits. Refrigeration is exponentially inefficient as T=>0 and the gap of a quantum system which sets the temperature you must cool to shrinks as you couple new degrees of freedom. This dynamic has been the basic reason for the sub exponential progress in the area (despite exponential expenditure)
    - abdullahkhalids 3y ago
      Not for photonic quantum computing. Only detectors require cooling, and it is possible to build adequately sized quantum computers with constant number of detectors using loop based architectures. Even more realistic architectures are very very cost effective on the number of components https://quantumfrontiers.com/2023/06/21/what-is-the-logical-gate-speed-of-a-photonic-quantum-computer/ https://quantumfrontiers.com/2023/06/21/what-is-the-logical-...
      - pclmulqdq 3y ago
        Yeah, it always struck me as odd that the main quantum computing research labs went for the "VLSI" approach straight away rather than building room-sized computers with qbits that are known to be more stable and don't require such aggressive refrigeration. Between the costs of refrigeration/fabrication and the increased speed of decoherence, it's not hard to imagine that the approach of using superconducting qbits may be a dead end, despite quantum ECC.
        abdullahkhalids 3y ago
        There are very valid reasons for this. Historically, this is what happened. * People did very basic qubit experiments with NMR in the late 90s. Very noisy experiments. * Around 2000 they realized photonic quantum computers would be "easiest" because light experiences very little noise. The problem was that its insanely difficult to do non-linear interactions between photons (which is necessary to do any sort of non-trivial classical or quantum computing with photons). In 2001, somebody came up with a clever way of doing non-linear interactions by using fast detectors. * Huge efforts started to try and build photonic quantum computers. Unfortunately, around 2004-05, people started to do estimates and it turned out that the number of sources and detectors needed with the clever way was humongous. Far more than we could hope to achieve, and there didn't seem to be any way of reducing it. People abandoned photonic quantum computing and started doing ion traps and superconducting. * Interestingly around the same time in 2005, there emerged an alternate method of building photonic quantum computers, based on "cluster states". However, the method also had the same humongous resource problem, but it had an advantage: the framework could be modified and played with to improve it. Over the next two decades, very slowly people figured out improvement after improvement to this architecture to bring down the resource costs. * At this point, this cluster-state photonic architecture has improved quite a bit and is starting to become very competitive with ion traps and superconducting qubits. PsiQuantum (whose article I shared above) is the leader in this right now. And they might win the race.
- laxd 3y ago
  > ... quantum computers are really early in their development and can't do the more complicated things yet. It's like if we had calculators that took an hour to do each arithmetic operation ... Reminds me of the story George Stibitz tells after developing one of the first devices that could be called a computer. Management at Bell Labs was not impressed that he had built a "20000 dollar calculator". https://youtu.be/qundvme1Tik?t=259 https://youtu.be/qundvme1Tik?t=259
  - hcks 3y ago
    Well a “20000 dollar calculator” is something QC can only dream of
mistermann 3y ago
A potential hidden bonus: if quantum computing theories get enough attention, maybe people will start to consider using the quantum computing abilities of the human mind with conscious intentionality (since by the time we get computers to be able to do it, it may be too late)!
- wholinator2 3y ago
  What are these capabilities of which you speak? Or have i missed the sarcasm
  - kelseyfrog 3y ago
    In many other worlds gp got tremendous karma for their post. That's how quantum mental abilities work.
    - ithkuil 3y ago
      Do you mean; Use a quantum random number generator and emit random words. Changes are that in some world the comment is insightful?
  - mistermann 3y ago
    Well, generate reality for one. It's not a trivial detail, but it tends to be dismissed or taken for granted (or downvoted lol). Someone may venture into this territory some day, and perhaps that someone will find some travelling companions to make the journey more exciting and productive....time will tell!
    - weard_beard 3y ago
      The trick is you can only flip as yet unobserved bits. If we know the asteroid is coming we can't delete it.
      - mistermann 3y ago
        Some bits can even be flipped in broad daylight while everyone's watching. One of the most popular ways to flip bits is by telling stories in which the bits have been flipped.
wouldbecouldbe 3y ago
Quantum computing feels like nucleair fusion. Been hearing about how its going to change the world since I was kid.
- deleted 3y ago
  [deleted]
- hedora 3y ago
  Well, in fairness, I could say the same about solar, improved batteries, etc.
  - marricks 3y ago
    > solar, improved batteries Neither of those sounded as sexy (i.e hyped) to me a nuclear fusion and quantum computers.
    - imchillyb 3y ago
      > solar, improved batteries >> Neither of those sounded as sexy (i.e hyped) to me a nuclear fusion and quantum computers. Breaking News: The Gates Foundation has actually deployed a product -- Solary! Meet Solary, The Gates Foundation replacement for salaries and a new way to power your entire home. This $1,000 (price pending review) device can provide a multi-family, multi-story, dwelling with power for 100 years. The software called Solary GoFY (possibly a subscription service) serves as a full and complete monitoring solution for the premises! -- See, solar can be sexy!
      - Dylan16807 3y ago
        Eh? A random person making up a fictional press release doesn't count as hype, you know that right?
  - skywhopper 3y ago
    Solar has become incredibly inexpensive in the last decade, and batteries likewise are many times better than they were 20 years ago. Is there further to go, yes, but progress has been steady and real applications are all around you for both. Our phones are marvels of battery technology that was impossible 15 years ago. Fusion and quantum computing on the other hand. Neither has yet solved one problem or made net progress. They have great promise but the practicalities may ultimately outweigh the benefits. Meanwhile, solar-charged batteries powering high performance electric cars are more common every day.
fnordpiglet 3y ago
It’s a milestone on a roadmap. Science like this doesn’t happen in eureka moments - it’s a methodical slog through our ignorance where we latch in wins bit by bit over decades. Quantum computing, AI, fusion, curing cancer, ending aging, they’re pinnacle achievements at the extended play of Civilization.
gaze 3y ago
The field of quantum computing HAS to have incremental results, or else nobody will continue to fund it. Unfortunately, it doesn't seem to be presenting great opportunities for incremental results. This doesn't invalidate the field, it just means that it's really hard to tell if you're going to see a pay-off. These things aren't really factored into the risks that investors think they're taking, so it's giving me a weird feeling in the pit of my stomach. I desperately want to see quantum computing work -- I've worked on it for 15 years now. From my vantage point, I see progress, but that's progress in making better qubits, better gates, better architectures, not solving problems. There's an error correction threshold, remember, and you start seeing real results when/if you cross it. Anyhow, with all these huge beautiful dilution fridges with their fancy gold plating and all that, the expense of QC is a rounding error relative to AI. It's still high-risk/high-reward and has seen a level of investment that's commensurate with that. Also, I don't know who all thinks that these physicists like myself are making beaucoup bucks working on QC. I make far less than a software engineer at grubhub or something, and have taken the opportunity cost of getting a PhD and all that.

tedivm 3y ago

I don't think it's that the concepts are contrived (although the test cases certainly are), it's just that our quantum computers are really early in their development and can't do the more complicated things yet. It's like if we had calculators that took an hour to do each arithmetic operation- the fact that people wouldn't use it doesn't mean arithmetic is contrived, just that it isn't as powerful as better alternatives. As the quote mentions, we'll need "many thousand qubits" to reach the point where society itself is getting new benefits out of things. These contrived cases help figure out how to scale the whole system.

upofadown 3y ago
It's more like if we had calculators that could not do any arithmetic operation at all... Someone someday might figure out how to make the calculator actually calculate, but not yet.
AbrahamParangi 3y ago
There's a fundamental question as to whether or not it's exponentially difficult to add additional qubits. If each marginal qubit is 5% more difficult to add as the previous one the task would be essentially impossible - and even if it wasn't impossible it would turn out to basically be cheating (in that you would be doing exponential work via either the quantum computing route or the conventional route).
- alpineidyll3 3y ago
  Note: that there is good physical reasons why the cost of QC may grow exponentially with qbits. Refrigeration is exponentially inefficient as T=>0 and the gap of a quantum system which sets the temperature you must cool to shrinks as you couple new degrees of freedom. This dynamic has been the basic reason for the sub exponential progress in the area (despite exponential expenditure)
  - abdullahkhalids 3y ago
    Not for photonic quantum computing. Only detectors require cooling, and it is possible to build adequately sized quantum computers with constant number of detectors using loop based architectures. Even more realistic architectures are very very cost effective on the number of components https://quantumfrontiers.com/2023/06/21/what-is-the-logical-gate-speed-of-a-photonic-quantum-computer/ https://quantumfrontiers.com/2023/06/21/what-is-the-logical-...
    - pclmulqdq 3y ago
      Yeah, it always struck me as odd that the main quantum computing research labs went for the "VLSI" approach straight away rather than building room-sized computers with qbits that are known to be more stable and don't require such aggressive refrigeration. Between the costs of refrigeration/fabrication and the increased speed of decoherence, it's not hard to imagine that the approach of using superconducting qbits may be a dead end, despite quantum ECC.
      - abdullahkhalids 3y ago
        There are very valid reasons for this. Historically, this is what happened. * People did very basic qubit experiments with NMR in the late 90s. Very noisy experiments. * Around 2000 they realized photonic quantum computers would be "easiest" because light experiences very little noise. The problem was that its insanely difficult to do non-linear interactions between photons (which is necessary to do any sort of non-trivial classical or quantum computing with photons). In 2001, somebody came up with a clever way of doing non-linear interactions by using fast detectors. * Huge efforts started to try and build photonic quantum computers. Unfortunately, around 2004-05, people started to do estimates and it turned out that the number of sources and detectors needed with the clever way was humongous. Far more than we could hope to achieve, and there didn't seem to be any way of reducing it. People abandoned photonic quantum computing and started doing ion traps and superconducting. * Interestingly around the same time in 2005, there emerged an alternate method of building photonic quantum computers, based on "cluster states". However, the method also had the same humongous resource problem, but it had an advantage: the framework could be modified and played with to improve it. Over the next two decades, very slowly people figured out improvement after improvement to this architecture to bring down the resource costs. * At this point, this cluster-state photonic architecture has improved quite a bit and is starting to become very competitive with ion traps and superconducting qubits. PsiQuantum (whose article I shared above) is the leader in this right now. And they might win the race.
laxd 3y ago
> ... quantum computers are really early in their development and can't do the more complicated things yet. It's like if we had calculators that took an hour to do each arithmetic operation ... Reminds me of the story George Stibitz tells after developing one of the first devices that could be called a computer. Management at Bell Labs was not impressed that he had built a "20000 dollar calculator". https://youtu.be/qundvme1Tik?t=259 https://youtu.be/qundvme1Tik?t=259
- hcks 3y ago
  Well a “20000 dollar calculator” is something QC can only dream of

mistermann 3y ago

A potential hidden bonus: if quantum computing theories get enough attention, maybe people will start to consider using the quantum computing abilities of the human mind with conscious intentionality (since by the time we get computers to be able to do it, it may be too late)!

wholinator2 3y ago
What are these capabilities of which you speak? Or have i missed the sarcasm
- kelseyfrog 3y ago
  In many other worlds gp got tremendous karma for their post. That's how quantum mental abilities work.
  - ithkuil 3y ago
    Do you mean; Use a quantum random number generator and emit random words. Changes are that in some world the comment is insightful?
- mistermann 3y ago
  Well, generate reality for one. It's not a trivial detail, but it tends to be dismissed or taken for granted (or downvoted lol). Someone may venture into this territory some day, and perhaps that someone will find some travelling companions to make the journey more exciting and productive....time will tell!
  - weard_beard 3y ago
    The trick is you can only flip as yet unobserved bits. If we know the asteroid is coming we can't delete it.
    - mistermann 3y ago
      Some bits can even be flipped in broad daylight while everyone's watching. One of the most popular ways to flip bits is by telling stories in which the bits have been flipped.

wouldbecouldbe 3y ago

Quantum computing feels like nucleair fusion. Been hearing about how its going to change the world since I was kid.

deleted 3y ago
[deleted]
hedora 3y ago
Well, in fairness, I could say the same about solar, improved batteries, etc.
- marricks 3y ago
  > solar, improved batteries Neither of those sounded as sexy (i.e hyped) to me a nuclear fusion and quantum computers.
  - imchillyb 3y ago
    > solar, improved batteries >> Neither of those sounded as sexy (i.e hyped) to me a nuclear fusion and quantum computers. Breaking News: The Gates Foundation has actually deployed a product -- Solary! Meet Solary, The Gates Foundation replacement for salaries and a new way to power your entire home. This $1,000 (price pending review) device can provide a multi-family, multi-story, dwelling with power for 100 years. The software called Solary GoFY (possibly a subscription service) serves as a full and complete monitoring solution for the premises! -- See, solar can be sexy!
    - Dylan16807 3y ago
      Eh? A random person making up a fictional press release doesn't count as hype, you know that right?
- skywhopper 3y ago
  Solar has become incredibly inexpensive in the last decade, and batteries likewise are many times better than they were 20 years ago. Is there further to go, yes, but progress has been steady and real applications are all around you for both. Our phones are marvels of battery technology that was impossible 15 years ago. Fusion and quantum computing on the other hand. Neither has yet solved one problem or made net progress. They have great promise but the practicalities may ultimately outweigh the benefits. Meanwhile, solar-charged batteries powering high performance electric cars are more common every day.

fnordpiglet 3y ago

It’s a milestone on a roadmap. Science like this doesn’t happen in eureka moments - it’s a methodical slog through our ignorance where we latch in wins bit by bit over decades. Quantum computing, AI, fusion, curing cancer, ending aging, they’re pinnacle achievements at the extended play of Civilization.

gaze 3y ago

The field of quantum computing HAS to have incremental results, or else nobody will continue to fund it. Unfortunately, it doesn't seem to be presenting great opportunities for incremental results. This doesn't invalidate the field, it just means that it's really hard to tell if you're going to see a pay-off. These things aren't really factored into the risks that investors think they're taking, so it's giving me a weird feeling in the pit of my stomach. I desperately want to see quantum computing work -- I've worked on it for 15 years now. From my vantage point, I see progress, but that's progress in making better qubits, better gates, better architectures, not solving problems. There's an error correction threshold, remember, and you start seeing real results when/if you cross it. Anyhow, with all these huge beautiful dilution fridges with their fancy gold plating and all that, the expense of QC is a rounding error relative to AI. It's still high-risk/high-reward and has seen a level of investment that's commensurate with that. Also, I don't know who all thinks that these physicists like myself are making beaucoup bucks working on QC. I make far less than a software engineer at grubhub or something, and have taken the opportunity cost of getting a PhD and all that.