I made the attempt, but couldn’t parse that first link.

Fair - it is indeed difficult for non-experts. But all you need to see from it is that it is a concrete example of a (small) actual quantum computer as reported on outside a corporate press release. The focus on error correction comes from the fact that this is the next big hurdle in the way of scaling up. But the machine is there!

This is just one more kind of chip that will be found in computers of the future.

Exactly - this was never meant to replace classical computers, but to do things that are impossible for classical computers to ever do.

Problem is, this only works for systems that have a known answer (like cryptography) with a verifiable result, otherwise the system never knows when the equation is “complete”.

This isn’t quite right. It’s true, there’s never 100% certainty you have the right answer, but 99.99999% is usually good enough. A classical computer also isn’t 100% certain since it’s also technically just a “physics experiment”, but it has an extremely low error rate, like 10^(-20).

when they talk about speed, they aren’t exactly being forthright

Sure, quantum computers aren’t faster than a classical computer for now, and won’t be for a while. But exponential speedup means that the problems we can eventually solve with a quantum computer are literally impossible for a physical computer to ever solve. This part of the corporate hype speak is true. It’s a purely physical fact. Though for sure we aren’t there yet!

it’s… not really useful in power expenditure or financially to do much beyond a large corporation or government breaking encryption.

Indeed, very likely nobody is ever going to be doing personal computing on these, but they were never meant for that, they are meant for supercomputing level calculations.

Hell yes! I’d love to share some stuff.

One good example of a quantum computer is the Lukin group neutral atoms work. As the paper discusses, they managed to perform error correction procedures making 48 actual logical qubits and performing operations on them. Still not all that practically useful, but it exists, and is extremely impressive from a physics experiment viewpoint.

There are also plenty of meaningful reports on non-emulated machines from the corporate world. From the big players examples include the Willow chip from Google and Heron from IBM being actual real quantum devices doing actual (albeit basic) operations. Furthermore there are a plethora of smaller companies like OQC and Pasqal with real machines.

On applications, this review is both extensive and sober, outlining the known applications with speedups, costs and drawbacks. Among the most exciting are Fermi-Hubbard model dynamics (condensed matter stuff), which is predicted to have exponential speedup with relatively few resources. These all depend on a relatively narrow selection of tricks, though. Among interesting efforts to fundamentally expand what tricks are available is this work from the Babbush group.

Let me know if that’s not what you were looking for.

Indeed I did. They seem to be pointing to the fact that current machines are not factoring primes in any serious way.

Does this contradict my point?

Prime factorisation is indeed nobody’s primary idea of what a quantum computer will be useful for in practice any time soon, but it cannot be denied that Shor’s algorithm is the first and only method of prime factorisation we have discovered which can finish in realistic time with realistic resources.

And that means that RSA is no longer as safe as it once was, justifying the process of finding alternatives.

Quantum science is not fraudulent, incredible leaps are being made with the immense influx of funding.

Quantum industry is a different beast entirely, with scientific rigour being corrupted by stock price management.

It’s an objective fact that quantum computers indeed exist now, but only at a very basic prototype level. Don’t trust anything a journalist says about them, but they are real, and they are based on technology we had no idea if would ever be possible.

Except quantum computers do indeed exist right now, and did not in the 90’s. Sadly, the hype and corporate interests still make it difficult to tell truth from nonsense.