Your objective
Describe the protocol of quantum teleportation, identify the required quantum resources, and trace through the steps that reconstruct an unknown quantum state at a distant location.
7.1 Protocol Overview
Steps: (1) Share an entangled pair, (2) Perform Bell‑basis measurement on the unknown qubit and one half of the pair, (3) Send the two classical bits, (4) Apply appropriate Pauli corrections to the remote qubit.
Sender: Bell measurement → 2 classical bits Receiver: Conditional Pauli corrections → Recreated state
7.2 Quantum Resources
Requires one maximally entangled pair (e.g., Bell state |Phi⁺⟩) shared between sender and receiver, plus two classical bits of communication.
Entangled pair: (|00⟩ + |11⟩)/√2
7.3 Example
Teleport the state α|0⟩ + β|1⟩ using the protocol; after correction the receiver obtains the exact same state.
Result: Exact recreation of the original state
Put it together
Worked example
Teleport |ψ⟩ = (1/√3)|0⟩ + (√(2/3))|1⟩ using an entangled pair |Phi⁺⟩. After measurement outcome 10, apply X then Z to the receiver’s qubit, yielding the original state.
Key takeaways
• Teleportation moves quantum information without moving the physical carrier. • Requires entanglement + classical communication. • The original state is destroyed, preserving no‑cloning theorem.
Knowledge check / 3 questions