I am watching this video in which a programming language for quantum computing is introduced. There is code like this:
// Inside TeleportClassicalMessage function
let msg = register[0]; // Initialized to |0⟩ state
let there = register[1]; // Initialized to |0⟩ state
// Inside Teleport function
let here = register[0]; // Initialized to |0⟩ state
H(here); // here is now |+⟩
CNOT(here, there); // 'here' and 'there' are now entangled as the Bell state
CNOT(msg, here); // What does this do?
For those of you not familiar with coding, what it seems to be doing is feeding $|+⟩$ (control) and $|0⟩$ (target) to a CNOT gate, which creates the entangled Bell state. Then it takes the first qubit out of that state, here
(without examining it), and feeds $|0⟩$ and here
to a CNOT gate again.
What exactly does this do?
msg
is initialised to $\lvert0\rangle$? Because if it is, then the second CNOT is not active and does nothing $\endgroup$