hetscop

(typed this out yesterday before @ZickZack s excellent answer, but couldn't post it at the time due to maintenance...)

No, you've got it wrong. This is a fairly common missunderstanding which is perpetuated by a lot of coverage about the topic being sloppy.

You could argue that there is a grain of truth to the idea of processing multiple possibilities at once, but it's a bit more complicated than that and the way it's usually presented leads to people building a bad intuition of how it works. If you do get in to the nitty-gritty of Shors algorithm it feels to me at least a bit like a weird hack that shouldn't work at all or at least not be faster than the normal way to compute prime factors. It isn't a general speedup, just in certain cases where you can exploit quantum mechanics in clever ways.

Of the top of my head the SMBC comic about it is actually pretty good. This article makes basically the same points, but a bit more elaborated (note that it was written a while ago so the part about the current state of quantum computing is outdated). I noticed that Veritasum put out a YouTube video which I haven't watched, but he is in my experience good at explaining physics and math so I think that there's a good chance that it'll hold up. I remember liking this Minute Physics video about Shor's algorithm too, if you wanna get a better understanding of it.

I should clarify that I'm not a quantum phycisist, I've just done a couple of internet deep dives on the topic but I can't say that I fully understand quantum computing at all. I do think my understanding of it is better than the one in this article and others like it.

Been gone for a couple of days

I thought that emojis didn't fit in with the aesthetics of reddit and they don't fit in with the aesthetics of kbin either. That said, emoji hate on reddit was dumb and performative because it wasn't about a slight aesthetic preference, it was about seeming cool to the ingroup by attacking people for being normies

This is article is missleading about how quantum computing works.

Superposition increases the computing power of a quantum computer exponentially. For example, two qubits can exist in four states simultaneously (00, 01, 10, 11), three qubits in eight states, and so on. This allows quantum computers to process a massive number of possibilities at once.

Quantum computers aren't faster because they "process" multiple "possibilities" at once. Quantum computers aren't any faster than regular computers when it comes to general purpose computing. You can exploit some interesting properties about quantum computing to solve certain problems asymptotically faster, like with Shor's algorithm.

This means that the time to solve a problem as the size of the problem grows scales better. Using Shor's algorithm, the time to factor a polynomial is proprtional to (log N)^2 log log N, where N is the size of the input data, instead of the fastest known non-quantum algorithm which takes time proportional to e^(1.9(log N)^(1/3)(log log N)^(2/3)). Note that the majority of problems that we would maybe like to solve using a computer don't have any fancy quantum algorithms asociated with them and as such are no faster than a normal computer,

Given a large enough problem that can be solved with a quantum algorithm, a quantum computer will eventually outperform a non-quantum computer. This does not mean that quantum computers can solve arbitrary problems quickly.

neomut, because I have linux brain damage