I've started learning Quantum Computing from the Qiskit Textbook and was able to easily understand or work out everything until it came to the working of Quantum Teleportation
I can understand the procedure of it, but cannot understand why it works and was unable to work out the math of it. I also couldn't find any source that explained this is in a more simplistic manner.
Here's the procedure that I have copy-pasted from the textbook:
Step 1: Alice and Bob create an entangled pair of qubits and each one of them holds on to one of the two qubits in the pair.
The pair they create is a special pair called a Bell pair. In quantum circuit language, the way to create a Bell pair between two qubits is to first transfer one of them to the Bell basis ( |+⟩ and |−⟩ ) by using a Hadamard gate, and then to apply a CNOT gate onto the other qubit controlled by the one in the Bell basis.
Let's say Alice owns q1 and Bob owns q2 after they part ways.
Step 2: Alice applies a CNOT gate on q1 , controlled by |ψ⟩ (the qubit she is trying to send Bob).
Step 3: Next, Alice applies a Hadamard gate to |ψ⟩ , and applies a measurement to both qubits that she owns - q1 and |ψ⟩ .
Step 4: Then, it's time for a phone call to Bob. She tells Bob the outcome of her two qubit measurement. Depending on what she says, Bob applies some gates to his qubit, q2 . The gates to be applied, based on what Alice says, are as follows :
00 → Do nothing
01 → Apply X gate
10 → Apply Z gate
11 → Apply ZX gate
Note that this transfer of information is classical.
And voila! At the end of this protocol, Alice's qubit has now teleported to Bob.