>>14359366>possibleIn principle yes, there's nothing in our fundamental understanding of physics stopping them from existing. But we might also be missing some fundamental understanding to begin with. This is why experimental physics efforts to build a QC is interesting, even from a purely academic standpoint.
>extremely beneficialMaybe, in extremely niche applications. "Extremely beneficial" is a huge overstatement.
>we've been trying since the 70sNo, the idea of a QC wasn't even conceived of until the mid 80s, and there was little to no interest in it until Shor's algorithm in the mid 90s. One could argue that quantum information theory got started in the 70s by Holevo, but he wasn't thinking anything about doing computations or algorithms with the notion.
>we're still not very close to actually doing itAs far as anything practical goes, that's right. Fault-tolerant QCing is decades away at best. But noisy quantum devices with 50-100 qubits exist now, and they are interesting to study as physical systems themselves - modestly sized, controllable quantum systems with lots of "unwanted" interactions with a classical environment.
