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I think you have serious conceptual holes in your understanding of the post. > The issues that Kalai poses as to the validity of the experiments done by Google

I think you have serious conceptual holes in your understanding of the post. > The issues that Kalai poses as to the validity of the experiments done by Google’s Quantum AI Lab is that the difference between the ideal distribution D and sampled distribution D’ is meaningfully different enough from each other, that significant results cannot be obtained from the experiment in comparing performance to classical simulations. This is categorically false. Can you quote the passage(s) that lead you to this conclusion?

lawrenceyan 7y ago
> By creating a 0-1 distribution we mean sampling sufficiently many times from that distribution D so it allows us to show that the sampled distribution is close enough to D. Because of the imperfection (noise) of qubits and gates (and perhaps some additional sources of noise) we actually do not sample from D but from another distribution D’. However if D’ is close enough to D, the conclusion that classical computers cannot efficiently sample according to D’ is plausible.
- computerex 7y ago
  The passage you quoted is under the: > Achieving quantum supremacy via sampling Headline and is simply describing some technical details of the experiment. This is not the author bringing any points of contention, there is no disagreement here at all, this is merely defining the criteria for how quantum supremacy is defined. I highlighted his points of contention as a response to your original comment that said he is nitpicking, here: https://news.ycombinator.com/item?id=21168813 https://news.ycombinator.com/item?id=21168813 His main point of contention seems to be: They need to understand the D' distribution more by running the experiment on lower qubit configurations, comparing the experimentally sampled distributions with one another across qubit configurations and across multiple runs of the same qubit configurations. As it is, he says that they may not have even sampled from D'. The burden of proof is on the experimenters to quantitatively show that they did. There were other issues raised, like Google not being quantitative enough with their claims of the gains achieved in their supremacy statement. He also brings up a more general issue with quantum computing in correlated errors, which are described in more detail in his paper here: http://www.ma.huji.ac.il/~kalai/Qitamar.pdf http://www.ma.huji.ac.il/~kalai/Qitamar.pdf But it boils down to that qubit logic gates experience positively correlated errors, which unless corrected with quantum fault tolerance will have an impact on any result. I hope this clears up some misconceptions. In general it is a good idea to use the principle of charity and try to address the best possible interpretation of someone's argument. This is true even more so when commenting on someone who is literally close to the top in their field.

lawrenceyan 7y ago

> By creating a 0-1 distribution we mean sampling sufficiently many times from that distribution D so it allows us to show that the sampled distribution is close enough to D. Because of the imperfection (noise) of qubits and gates (and perhaps some additional sources of noise) we actually do not sample from D but from another distribution D’. However if D’ is close enough to D, the conclusion that classical computers cannot efficiently sample according to D’ is plausible.

computerex 7y ago
The passage you quoted is under the: > Achieving quantum supremacy via sampling Headline and is simply describing some technical details of the experiment. This is not the author bringing any points of contention, there is no disagreement here at all, this is merely defining the criteria for how quantum supremacy is defined. I highlighted his points of contention as a response to your original comment that said he is nitpicking, here: https://news.ycombinator.com/item?id=21168813 https://news.ycombinator.com/item?id=21168813 His main point of contention seems to be: They need to understand the D' distribution more by running the experiment on lower qubit configurations, comparing the experimentally sampled distributions with one another across qubit configurations and across multiple runs of the same qubit configurations. As it is, he says that they may not have even sampled from D'. The burden of proof is on the experimenters to quantitatively show that they did. There were other issues raised, like Google not being quantitative enough with their claims of the gains achieved in their supremacy statement. He also brings up a more general issue with quantum computing in correlated errors, which are described in more detail in his paper here: http://www.ma.huji.ac.il/~kalai/Qitamar.pdf http://www.ma.huji.ac.il/~kalai/Qitamar.pdf But it boils down to that qubit logic gates experience positively correlated errors, which unless corrected with quantum fault tolerance will have an impact on any result. I hope this clears up some misconceptions. In general it is a good idea to use the principle of charity and try to address the best possible interpretation of someone's argument. This is true even more so when commenting on someone who is literally close to the top in their field.