Question about the Unitary Operation in Teleportation

[al onestone]

Question about the "Unitary Operation" in Teleportation

How is the unitary operation actually performed in quantum teleportation(by Bob)? I can never seem to find a thorough explanation of this when I look up teleportation in the literature or on the internet. I understand that Bob's particle is in an unentangled state described by a single qubit pure state, but that it has to be transformed(via a unitary operation) to the original state of Alice's qubit. If you look at it in a real experimental picture, Bob not only has to transform the particle, but he has to distinguish the specific particle which requires the transformation. This means identifying one particle in a whole beam(like a needle in a haystack) and then perform the unitary operation exclusively on it. How is this accomplished? Is Bob somehow able to separate the four possible teleported states without having received the classical message from Alice or does he need to wait for the transmission before he even identifies the correct particle?

 

[DrClaude]

How is the unitary operation actually performed in quantum teleportation(by Bob)?

The procedure is explained in the "Formal presentation" section of the Wikipedia article:
https://en.wikipedia.org/wiki/Quantum_teleportation#Formal_presentation

If you look at it in a real experimental picture, Bob not only has to transform the particle, but he has to distinguish the specific particle which requires the transformation.

Bob should be able to know in advance which is particle that is entangled with one of Alice's particles...

Is Bob somehow able to separate the four possible teleported states without having received the classical message from Alice or does he need to wait for the transmission before he even identifies the correct particle?

He needs to know what Alice has measured. Otherwise, the best he can do is apply one of the 4 possible transformations randomly and hope he chose correctly.