Device-independent certification of the teleportation of a qubit

Abstract

We want to certify in a black-box scenario that two parties simulating the teleportation of a qubit are really using quantum resources. If active compensation is part of the simulation, perfect teleportation can be faked by purely classical means. If active compensation is not implemented, a classical simulation is necessarily imperfect: In this case, we provide bounds for the certification of quantumness using only the observed statistics. In particular, if a uniform shrinking of the Bloch vector is observed on the teleported side, an average teleportation fidelity of 85% guarantees the use of quantum resources. In general, the criterion is not simply related to the fidelity; in an extreme case, the assessment of quantumness can be positive even for an average fidelity as low as 50%. © 2013 American Physical Society.