One of the question while I discussed with my colleague in the math department was the construction of oracle circuit.
In computer science, specifically in algorithm, we take oracle as granted and treat it as a black box to analyze our problem.
However, he raised the question that given the oracle function, can the circuit be constructed in a reversible way; namely, unitary oracle common in well-known algorithm. He thought that the input may be subjected to phase kickback.
My question is given the oracle function. Can’t we use the reversible computation defined in classical computer to construct this oracle circuit?