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> Can these computers actually do something better than their classical counterparts, right now? The answer is yes. Sometimes this is referred to as 'quantum s

> Can these computers actually do something better than their classical counterparts, right now? The answer is yes. Sometimes this is referred to as 'quantum supremacy' and some researchers at Google declared it in 2019. https://www.nature.com/articles/s41586-019-1666-5 https://www.nature.com/articles/s41586-019-1666-5 https://ai.googleblog.com/2019/10/quantum-supremacy-using-programmable.html https://ai.googleblog.com/2019/10/quantum-supremacy-using-pr...

isoprophlex 4y ago
Thanks, interesting idea but it seems the practical applicability is still far away. > One of the most celebrated results in quantum computing is the development of a quantum algorithm for factorization that works in time polynomial in n. This algorithm, due to Peter Shor and known as Shor’s algorithm, runs in O (n3 log n) time and uses O (n2 log n log log n) gates. The first experimental implementation of this algorithm on a quantum computer was reported in 2001, when the number 15 was factored. The largest integer factored by Shor’s algorithm so far is 21.
YakBizzarro 4y ago
Quantum supremacy, while a very interesting experiment and a milestone in quantum computing, proves hardly anything about usefulness of quantum computers. It "only" proves that quantum computers are the best quantum computers, and classic ones can't efficiently simulate them. It say nothing about useful operations.
- s1dev 4y ago
  From a theoretical point of view, this is evidence that quantum computing is a more powerful model of computation. I think it would be hard to argue that a model of computation that can solve more problems is any less useful. Applications like quantum simulation do appear to be difficult on a classical computer yet efficiently computable on a quantum computer
  - kbelder 4y ago
    Basketball is hard to simulate on a classical computer, but easy to simulate by playing a game of basketball.
oldgradstudent 4y ago
In what sense the result describes a computation? And it what sense the device describes is a computer? The only thing it can do faster is to run itself. It's as if I called a Boeing airliner an aerodynamic computer and each flight a computaion.
- krastanov 4y ago
  They are programmable, that makes them drastically more intetesting than a single-parameter aerodynamic analog computer like the Boeing, from the point of view of Computational Complexity. It does not make them "useful" yet, but it is a big milestone. See https://scottaaronson.blog/?p=5460 https://scottaaronson.blog/?p=5460
  - oldgradstudent 4y ago
    Programmable, or parametrizable? In any test flight there are plenty of parameters set for the flight. Are aerodynamic computers programmable? But in any case, the mere existence of "quantum supremacy" research is a clear indication these are pointless contraptions.
    - krastanov 4y ago
      Could you elaborate on your last paragraph? Proof of concepts that can not solve "useful" problems seem like an incredibly important milestones to me? Or is your frustration that they are occasionally presented by overly enthusiastic engineers as more than "useless" technology demonstrators (with this frustration I would agree). The second half of the article I shared covers the parametrization question you raised.
      - oldgradstudent 4y ago
        > Could you elaborate on your last paragraph? A successful technology does not need to show theoretical supremacy. Its proponents can simply show the useful services and products it makes. > Proof of concepts that can not solve "useful" problems seem like an incredibly important milestones to me? Sure, just don't claim supremacy until you can back it up with an actually reasonable definition of computation. > Or is your frustration that they are occasionally presented by overly enthusiastic engineers as more than "useless" technology demonstrators (with this frustration I would agree). It is hard to find any news about quantum computing that is not way over exaggerated. > The second half of the article I shared covers the parametrization question you raised. His argument may apply to the teapot example, but for, say, a test flight to fine tune the auto pilot behavior, there are plenty of inputs that can be set. I'd argue the aerodynamic computer supremacy example still stands.

isoprophlex 4y ago

Thanks, interesting idea but it seems the practical applicability is still far away. > One of the most celebrated results in quantum computing is the development of a quantum algorithm for factorization that works in time polynomial in n. This algorithm, due to Peter Shor and known as Shor’s algorithm, runs in O (n3 log n) time and uses O (n2 log n log log n) gates. The first experimental implementation of this algorithm on a quantum computer was reported in 2001, when the number 15 was factored. The largest integer factored by Shor’s algorithm so far is 21.

YakBizzarro 4y ago

Quantum supremacy, while a very interesting experiment and a milestone in quantum computing, proves hardly anything about usefulness of quantum computers. It "only" proves that quantum computers are the best quantum computers, and classic ones can't efficiently simulate them. It say nothing about useful operations.

s1dev 4y ago
From a theoretical point of view, this is evidence that quantum computing is a more powerful model of computation. I think it would be hard to argue that a model of computation that can solve more problems is any less useful. Applications like quantum simulation do appear to be difficult on a classical computer yet efficiently computable on a quantum computer
- kbelder 4y ago
  Basketball is hard to simulate on a classical computer, but easy to simulate by playing a game of basketball.

oldgradstudent 4y ago

In what sense the result describes a computation? And it what sense the device describes is a computer? The only thing it can do faster is to run itself. It's as if I called a Boeing airliner an aerodynamic computer and each flight a computaion.

krastanov 4y ago
They are programmable, that makes them drastically more intetesting than a single-parameter aerodynamic analog computer like the Boeing, from the point of view of Computational Complexity. It does not make them "useful" yet, but it is a big milestone. See https://scottaaronson.blog/?p=5460 https://scottaaronson.blog/?p=5460
- oldgradstudent 4y ago
  Programmable, or parametrizable? In any test flight there are plenty of parameters set for the flight. Are aerodynamic computers programmable? But in any case, the mere existence of "quantum supremacy" research is a clear indication these are pointless contraptions.
  - krastanov 4y ago
    Could you elaborate on your last paragraph? Proof of concepts that can not solve "useful" problems seem like an incredibly important milestones to me? Or is your frustration that they are occasionally presented by overly enthusiastic engineers as more than "useless" technology demonstrators (with this frustration I would agree). The second half of the article I shared covers the parametrization question you raised.
    - oldgradstudent 4y ago
      > Could you elaborate on your last paragraph? A successful technology does not need to show theoretical supremacy. Its proponents can simply show the useful services and products it makes. > Proof of concepts that can not solve "useful" problems seem like an incredibly important milestones to me? Sure, just don't claim supremacy until you can back it up with an actually reasonable definition of computation. > Or is your frustration that they are occasionally presented by overly enthusiastic engineers as more than "useless" technology demonstrators (with this frustration I would agree). It is hard to find any news about quantum computing that is not way over exaggerated. > The second half of the article I shared covers the parametrization question you raised. His argument may apply to the teapot example, but for, say, a test flight to fine tune the auto pilot behavior, there are plenty of inputs that can be set. I'd argue the aerodynamic computer supremacy example still stands.