Teleportation: from Probability Distributions to Quantum States

The role of the off-diagonal density-matrix elements of the entangled pair is investigated in the quantum teleportation of a qubit. The dependence between these elements and the off-diagonal elements of the teleported density matrix is shown to be linear. In this way ideal quantum teleportation is related to a completely classical communication protocol: the one-time pad cypher. The latter can be regarded as the classical counterpart of Bennett’s quantum-teleportation scheme. The quantum-to-classical transition is demonstrated by a gedankenexperiment. PACS numbers: 03.67.Hk, 03.65.Ta 1