3 ms·

Is this one of the first examples where a quantum computer is noticeably faster vs classical; or have there been past examples?

jhrmnn 5y ago
There have been past claims of quantum advantage that so far always turned out to be rather questionable when the details are discussed.
contravariant 5y ago
Well if we're counting every quantum interaction that would take a long time to solve on a classical computer as 'computational advantage' then arguably any nontrivial quantum interaction would do the trick. And as far as I can tell it's not calculating something that anyone would consider useful, so it's a bit debatable in what respect this result is any different. So well, it depends on your perspective I guess.
- clavigne 5y ago
  That's been the problem with the Google result too, even though they did have "controlled" operations. They basically showed that a quantum computer doing random operations has an output that is difficult to predict with classical simulation. It also solves no problem at all. They tried to shoehorn into the paper a "CSRNG" application but it's dubious at best if you have any kind of cost constraint.
tsimionescu 5y ago
The first successful quantum supremacy experiment, as accepted by the QC community in general, was proven by Google. Here's Scott Aaronson's write up on it: https://www.scottaaronson.com/blog/?p=4372 https://www.scottaaronson.com/blog/?p=4372 I believe there was also a second successful, but somewhat more controversial, experiment by a Chinese team.
- logicchains 5y ago
  >The first successful quantum supremacy experiment, as accepted by the QC community in general That's a debateable claim. IBM's QC team certainly doesn't accept it, and have demonstrated that what Google did could be done by a conventional computer: https://www.ibm.com/blogs/research/2019/10/on-quantum-supremacy/ https://www.ibm.com/blogs/research/2019/10/on-quantum-suprem...
  - johnebgd 5y ago
    IBM is also salty that they aren't considered "big tech" anymore. There is no I in FAANG.
  - just_temp 5y ago
    The main point of IBM was that by using RAM and Disk storage you could perform computations of the google system that were not as onerous as was put out in the google paper. That said, if you had an extra 10+ qubits (which is essentially what this new work does) you are back in the range where the supercomputer will be taking more time than is reasonable. For a quick eyeball imagine what adding 10+ qubits on to this kind of plot would do (from ibm post) https://www.ibm.com/blogs/research/wp-content/uploads/2019/10/sycamorecircuits.jpg https://www.ibm.com/blogs/research/wp-content/uploads/2019/1... Oh, and you need a lot of storage, just a couple of more qubits and it would not have been able to fit in the 250 PiB on Summit, so the IBM argument would have been void if google had 55 qubits in their work.

jhrmnn 5y ago

There have been past claims of quantum advantage that so far always turned out to be rather questionable when the details are discussed.

contravariant 5y ago

Well if we're counting every quantum interaction that would take a long time to solve on a classical computer as 'computational advantage' then arguably any nontrivial quantum interaction would do the trick. And as far as I can tell it's not calculating something that anyone would consider useful, so it's a bit debatable in what respect this result is any different. So well, it depends on your perspective I guess.

clavigne 5y ago
That's been the problem with the Google result too, even though they did have "controlled" operations. They basically showed that a quantum computer doing random operations has an output that is difficult to predict with classical simulation. It also solves no problem at all. They tried to shoehorn into the paper a "CSRNG" application but it's dubious at best if you have any kind of cost constraint.

tsimionescu 5y ago

The first successful quantum supremacy experiment, as accepted by the QC community in general, was proven by Google. Here's Scott Aaronson's write up on it: https://www.scottaaronson.com/blog/?p=4372 https://www.scottaaronson.com/blog/?p=4372 I believe there was also a second successful, but somewhat more controversial, experiment by a Chinese team.

logicchains 5y ago
>The first successful quantum supremacy experiment, as accepted by the QC community in general That's a debateable claim. IBM's QC team certainly doesn't accept it, and have demonstrated that what Google did could be done by a conventional computer: https://www.ibm.com/blogs/research/2019/10/on-quantum-supremacy/ https://www.ibm.com/blogs/research/2019/10/on-quantum-suprem...
- johnebgd 5y ago
  IBM is also salty that they aren't considered "big tech" anymore. There is no I in FAANG.
- just_temp 5y ago
  The main point of IBM was that by using RAM and Disk storage you could perform computations of the google system that were not as onerous as was put out in the google paper. That said, if you had an extra 10+ qubits (which is essentially what this new work does) you are back in the range where the supercomputer will be taking more time than is reasonable. For a quick eyeball imagine what adding 10+ qubits on to this kind of plot would do (from ibm post) https://www.ibm.com/blogs/research/wp-content/uploads/2019/10/sycamorecircuits.jpg https://www.ibm.com/blogs/research/wp-content/uploads/2019/1... Oh, and you need a lot of storage, just a couple of more qubits and it would not have been able to fit in the 250 PiB on Summit, so the IBM argument would have been void if google had 55 qubits in their work.