Experimental Realization of Continuous Variable Teleportation

Abstract

Quantum teleportation is a method of quantum state transportation with a classical channel and a quantum channel. In this technique, the “information” contained in a quantum state is transferred from a sending station (Alice) to a receiving station (Bob), with the original quantum state thereby reconstructed at Bob’s place with the received information and previously shared entanglement. Note that it is impossible to perform the state transformation represented by quantum teleportation only with a classical channel, which can be qualitatively explained as follows. If one attempts to obtain complete information with some particular measurement on an unknown quantum state of motion, for example, then both position and momentum (canonically conjugate variables) must be determined simultaneously with negligible error, which is of course impossible [2]. It is thus impossible for Alice to obtain complete information on the unknown quantum state, so that she certainly cannot send enough information for the reconstruction of the state to Bob. He then is unable to reconstruct the complete state at his place. By contrast, in quantum teleportation, Alice and Bob neatly circumvent constraints that would otherwise be imposed on Alice’s state measurement and Bob’s state generation, and are thereby able to reconstruct the original state at Bob’s place.