Brains are inherently chemical, and chemistry is just very abstracted quantum mechanics. Technically physical processors also hold quantum state, but we build them in a way that the abstracted state of 0s and 1s is portable. Brains didn't evolve such a requirement, and various quantum states maybe indirectly observable at the thought level.
I suspect if we can recreate a human based on data, we also can learn them pretty quickly. Take a language course?
Also brains are complex systems in action, with vast quantum data and momentum that would be infeasible to measure let alone store or recreate.
A brain scan no matter how detailed is unlikely to provide the information necessary reproduce a mental state.