Far from my expertise, but sheer curiosity. I've read that PostBQP ("a complexity class consisting of all of the computational problems solvable in polynomial time on a quantum Turing machine with postselection and bounded error") is very powerful. Still, I don't understand the practical sense of assuming you can decide the value an output qubit takes.
My question: Have post-selection quantum computing experiments been implemented (or is it possible that they will be implemented)? (And, if the answer is yes: how does post-selection take place in a way that practically enhances your computing power?)