Quantum Teleportation and Hidden Variables

TL;DR

This paper investigates whether quantum teleportation of a spin-1/2 state can be explained by local hidden-variable models, concluding that such models are incompatible with the process, thus emphasizing the inherently quantum nature of teleportation.

Contribution

It provides a no-go theorem showing the incompatibility of local hidden-variable models with quantum teleportation of spin-1/2 states.

Findings

Hidden-variable densities differ for two mathematical descriptions of teleportation.

Hidden-variable models cannot fully account for the teleportation process.

Conflict also appears in sequential measurements on a single spin-1/2 particle.

Abstract

In this paper we address the question as to what extent the quantum-mechanical nature of the process is relevant for teleportation of A spin-1/2 state. For this purpose we analyze the possibility of underpinning teleportation with a local-hidden-variable model. The nature of the models, which we consider as legitimate candidates, guarantees the classical character of all the probabilities which can be deduced from them. When we try to describe the teleportation process following two different mathematical routes, we find two different hidden-variable densities, which thus end up having a doubtful physical significance within the "reality" that a hidden-variable model tries to restore. This result we consider as a "no-go theorem" for the hidden-variable description of the teleportation process. We also show that this kind of conflict arises when considering successive measurements (one of which is selective projective) for one spin-1/2 particle.