I like to tell people that actual, programmable quantum computers do exist (which is a very important point—they’re not vaporware), but exactly like you say, in order to make them useful and scalable, more “actual science” needs to happen.
https://quantum-computing.ibm.com/composer/files/new
if you don't think these are computers then you just don't know what a computer really is
https://en.wikipedia.org/wiki/Circuit_(computer_science)
they're not useful at all but they're still real actual unadulterated computers.
wut? different QEC produce differently sized logical qubits and there are absolutely machines with enough physical qubits to amount to a logical qubit:
https://www.ncbi.nlm.nih.gov/books/NBK538709/#:~:text=In%20S....
and realized QEC is definitely not far off
https://www.nature.com/articles/ncomms7979
>for quantum computer to be of any use it should have >10k logical qubits
i'm aware and yet it's false to claim that these things don't compute. for the time being they're noisy computers but they're still computers.
It’s limited because it has only 3 bits, but if you play with the input bits, the output bits change!
btw the circuits in quantum circuits clearly aren't just combinational since they evolve in time.
“It’s not very useful but it can make computations” is a very low bar to pass, and very basic discrete (classical) logic can clear that without problems.
No squinting required.
There has been also very little if any actual research in other fields powered with quantum computing.
We can keep moving the goal posts and claim that we have made it, but the fact is that QC keeps overpromising and under delivering.
Well, great; that's an opinion. The thing is, if a device uses the quantum-mechanical properties of the universe to do calculation, then it is a quantum computer; asserting that it isn't one is a matter of semantics and categorization, since what you're really doing is redefining the term "quantum computer" to inherently include "gate model" as part of it, which is not a foregone conclusion yet.
I believe, from what I've read, that at this point current and projected gate-model quantum computers will not be competitive on optimization problems where quantum annealing will be, so there is definitely utility in continuing to pursue this research and development exercise.
> There has been also very little if any actual research in other fields powered with quantum computing.
Here's our latest:
https://science.sciencemag.org/content/early/2021/07/14/scie...
As a physics playground, annealers are very compelling, and materials research will definitely benefit from these devices.
Except this definition includes classical computers as well. At the scales of current transistors, quantum effects are required to explain their inner workings, and they are used to perform computations.
10 qubits is enough to simulate a pair of particles interacting already.