Is Teleportation a (quantum) mystery?

Abstract

Since its discovery quantum teleportation has often been seen as a manifestation, indeed the epitome, of the very paradoxical and mysterious nature of quantum theory itself. It is commonly regarded as genuinely quantum and essentially paradoxical. Although a common approach to teleportation amongst physicists nowadays is a somewhat operational one, some researchers are making an effort to deflate the above views. On the one hand, it was recently argued that the paradox of information transfer taking place in teleportation is dissolved (Timpson, 2006) by appealing the very notion of information. On the other hand, it was demonstrated that some classical versions of teleportation retain its important features, which hitherto were considered genuinely quantum (Cohen, 2003; Collins&Popescu, 2002; Hardy, 1999; Mor, 2006; Spekkens, 2007). I will present a special version of a quantum teleportation protocol which is in a sense split into classical and quantum steps. This description provides us with a unified picture of teleportation in both domains. It will be explicitly shown how classical teleportation is embedded in the quantum protocol. Moreover, the classical step can be successfully accomplished even if the state shared by the parties is completely disentangled [this is consistent with the result obtained in (Wang, 2005)]. Yet, all the (apparent) paradoxical features usually associated with quantum teleportation are clearly present in this step. In particular, this demonstrates that entanglement cannot be ultimately responsible and not necessary for the (paradoxical?) information transfer. Thus, even if one considers teleportation as mysterious, all its mysteries are shifted from quantum domain into purely classical one.