Proof that a quantum computer is equivalent to some logical circuit My question is about the quantum computer. I have tried to prove that the quantum computer is equivalent to some logical circuit.
I know this has already been proven, but I will present my attempt:


First we know that the quantum computer is composed of quantum logic gates
https://en.wikipedia.org/wiki/Fredkin_gate. According to this link, this gate is universal
So any quantum computer can be made up of those gates
Now we make a logical circuit simulating the Fredkin gate
Then each quantum circuit can be simulated by a logical circuit


Is this proof valid?
It's not a valid proof (yet) because you haven't described how you plan to do step 3.  You also haven't described how you plan to deal with superpositions of states.