Quantum Teleportation

Quantum teleportation moves the state of a qubit from one location to another without physically transporting the particle itself. The protocol needs three qubits: the qubit to be teleported, and an entangled pair (a Bell state) shared in advance between sender and receiver. The sender performs a joint (Bell-basis) measurement on their half of the entangled pair together with the qubit being teleported, which produces one of four possible two-bit outcomes and destroys the original qubit's state in the process, a direct consequence of the no-cloning theorem, which forbids a perfect copy from ever existing alongside the original. The sender transmits those two classical bits to the receiver over an ordinary channel, and the receiver applies one of four corresponding gates to their half of the entangled pair, which reconstructs the exact original state. Nothing here allows faster-than-light communication: the receiver's qubit carries no usable information until the classical bits arrive, and that transmission is bound by the speed of light. Teleportation is the core primitive behind quantum networking and distributed quantum computing, since it is how a qubit's state moves between nodes that are only linked by entanglement and a classical channel.