[Green_man]

Do other QM interpretations predict that quantum computers wouldn't be able to benefit from superposing N qubits over 2^N (possible) output states? As far as I understand, it's not just Copenhagen that allows for this.

Would an interpretation need to reject Bell's theorem to get there? Or could it not include superposition but still keep all of Bell's theorem?

[PeterWhittaker]

Rovelli’s work on relational QM suggests to me that superposition-as-real in the Copenhagen interpretation is false, a misunderstanding of how to incorporate the observer into the equation.

Once the observer (or the affected system, same thing, in the end) is incorporated, a lot of the things about superposition that needed interpretation disappear.

Read Helgoland for more.

(My physics degree was a long time ago and my math is quite out of date. While Rovelli doesn’t discuss QC in the book, his take on what superposition is not has strong implications for QC AFAICT.)

[dekken_]

Thanks for the suggestion. I have his other book "Order of time" (beside me no less) that I have yet to finish but have liked so far.

[PeterWhittaker]

That’s a good one, next in my reread list.