I'm an actual physicist here. Not in quantum computers, but that was my advisor's field and I've kept paying attention in the years since. Your intuition here is correct, I believe. Classical computer science deals with information processing limits of devices constructed using the classical physics laws of Newton and Maxwell. Quantum physics introduces new elements that permit new kinds of information processing machines, which have no obligation to be constrained by classical law.
I don't know of any computer scientists, including the quantum-information-theorists, who think that QTMs can compute something that classical TMs cannot. That is, QM cannot solve undecidable problems.
> Quantum physics introduces new elements that permit new kinds of information processing machines, which have no obligation to be constrained by classical law.
Question then becomes, how do you build such non-constrained machines? Also, how do you confirm that such machines—or even small scale prototypes—are not constrained by classic laws of physics?
> Question then becomes, how do you build such non-constrained machines? Also, how do you confirm that such machines—or even small scale prototypes—are not constrained by classic laws of physics?
By doing the math of many physics calculations to design a setup that will make these quantum phenomena stable enough to be useful, then building it and seeing if prediction matches reality.
