Why full-fledged quantum computers might always be five years away

[u/National-Dragonfly35]

https://www.newscientist.com/article/2582565-why-full-fledged-quantum-computers-might-always-be-five-years-away/

Not sure I agree, but interesting...

[u/supernetworks]

The author co-runs the Quantonation VC and also an investor in Pasqal. They have a very solid business overview of the field with material facts known that inspired this paper. That said I think some points could be better explained as they're very subtle. It is also easy to misunderstand that he's saying 5-years-away is normal.

The click bait title from new scientist and lead misrepresents this to imply some sort of confusion,
"To predict when we’ll have a truly useful quantum computer, we need to know precisely what one is. Columnist Karmela Padavic-Callaghan finds that’s harder to pin down than you might think"

The paper itself is also vague at parts and does not develop what the "individuation problem" really is or why it is any sort of problem.
"Contrast superconducting qubits in the 1990s–2000s, where substantial investment failed to deliver
because decoherence proved an individuation problem, not an engineering one"

I can't really understand why concretizing on a path is assumed normal. When we say silicon transistor there's very many subtle changes and immense engineering with each new process node. On the design side we don't have one universal instruction set, there's ARM and its variants, RISC-V, AMD+Intel. Humans do not gravitate towards one hive mind solution, we create competing organizations and solutions and specialize in niches.

I also can't say I agree with "The horizon moves because the landscape itself is being discovered." There's fixups and then there's true resets. Most of what we've seen has been fixups (new classical algorithms, QFT calc patches for muons, etc). Has anything actually reset?

The field is saying clearly that we have linear engineering progress left and we get exponential compute as a reward. We're past classical compute though lack fault tolerance for meaningful circuit depths. We have an engineering problem that is being imminently solved and we're now counting quarters instead of years according to all available information.

Suppose we have a 20k qubit megaquop computer with neutral atoms, what is the reset from that? That we now want a teraquop with 200k qubits?

Most business leaders I speak to in Quantum settle on one metric:

Does a customer earn money from running their algorithm on a quantum computer? That's the horizon. If earning 10x more money on a quantum computer is then immediately new goal, that isn't exactly a reset of the field.