Quantum Teleportation

Quantum Teleportation

Quantum teleportation is a foundational protocol that transfers an unknown quantum state from a sender (Alice) to a receiver (Bob) using only a shared entangled pair and two classical bits of communication, without physically moving the qubit itself and without ever learning the state being sent. It is a cornerstone of quantum communication and distributed quantum computing, underpinning quantum repeaters and gate teleportation in fault-tolerant architectures. This Cirq example implements the complete protocol: Alice and Bob first share a Bell pair; Alice then entangles the unknown message qubit with her half of the pair, measures both of her qubits in the appropriate basis, and sends the two classical measurement outcomes to Bob. Conditioned on those two bits, Bob applies the corresponding Pauli correction (X and/or Z) to his half of the entangled pair, which transforms it into an exact copy of the original message state. The script prepares the message qubit in a random state, runs the full circuit through simulation, and verifies that Bob's final qubit matches Alice's original, demonstrating that quantum information can be reliably transmitted using entanglement plus classical communication. It is a clear, end-to-end illustration of entanglement as a communication resource.

Run it

pip install -r requirements.txt
python quantum_teleportation.py

Source and license

Imported from examples/quantum_teleportation.py in quantumlib/Cirq at v1.6.1, under the Apache License 2.0. Original authors: The Cirq Developers. The upstream LICENSE is included alongside this example.