I think the idea is that it doesn’t matter if it takes billions of gates to achieve, the point is that it can do it very fast. If we thought a table sized FPGA could do it, a state actor would most definitely build one.

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lazide 6 days ago | parent [-]

theoretically

The practical problem is that ‘noise’ between gates seems to increase exponentially, so practically it may actually be impossible to construct anything with more than a handful of gates for the foreseeable (possibly indefinite?) future.

It’s essentially the crypto version of Fusion.

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EthanHeilman 6 days ago | parent [-]

Quantum error correction addresses this problem and we now have tech demos showing that we can build scalable QCs with surface codes [0].

[0] https://scottaaronson.blog/?p=8525

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Der_Einzige 6 days ago | parent | next [-]

This, like all other purported advancements in quantum error correction, is a meme with zero practical impact.

	▲	EthanHeilman 6 days ago \| parent [-]
		any sources? I'd be interested to read a critique of quantum error correction

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lazide 6 days ago | parent | prev [-]

Cool, so we should totally be able to factor 21 (or larger numbers)…. When?

	▲	EthanHeilman 6 days ago \| parent [-]
		You brought up gate noise, there has been quite a bit of progress on that problem. > so we should totally be able to factor 21 (or larger numbers)…. When? Just because we solve one problem doesn't imply all the problems in QC are also instantly solved. I guess it does if you assume noise is the only problem and once is it solved the engineering is trivial. That is not the case. Even assuming all foundational problems have been solved, figuring out how actually engineer and also mass produce large numbers of gates, will take a while. As the article pointed out, going from 15 to 21 requires a 100x increase in gates. As the article that you posted under says: "Because of the large cost of quantum factoring numbers (that aren’t 15), factoring isn’t yet a good benchmark for tracking the progress of quantum computers. If you want to stay abreast of progress in quantum computing, you should be paying attention to the arrival quantum error correction (such as surface codes getting more reliable as their size is increased) and to architectures solving core scaling challenges (such as lost neutral atoms being continuously replaced)."