For the treatment of teleportation of continuous quantum variables, often the Wigner functions are used. In this paper, we will show that by using the holomorphic representation of the canonical commutation relations (CCR), the teleportation of continuous quantum variables is treated in a parallel way as the teleportation of qubits.
Teleportation of optical field states (as continuous quantum variables) is usually described in terms of Wigner functions. This is in marked contrast to the theoretical treatment of teleportation of qubits. In this paper we show that by using the holomorphic representation of the canonical commutation relations, teleportation of continuous quantum variables can be treated in complete analogy to the case of teleportation of qubits. In order to emphasize this analogy, short descriptions of the basic experimental schemes both for teleportation of qubits and of continuous variables are included. We conclude our paper with a brief discussion of the effectiveness of our description of continuous variable teleportation and of the role of localization of quantum states in teleportation problems.
Two different teleportation protocols are investigated by using two pairs of canonically conjugated observables such as position-momentum and phase-number. The discrete variable and continuous variable quantum teleportation are unified in the framework of canonical quantum teleportation. Canonically conjugated observables are found to play a 3-fold role in the quantum teleportation. Firstly, the common eigenstate of two commuting canonical observables like phase-difference and number-sum provides the quantum channel between two systems. Secondly, a similar pair of canonical observables from another two systems is measured in the Bell operator measurements. Finally, two translations generated by the canonically conjugated observables of a single system constitute the local unitary operation to recover the unknown state.
The phase-space method is applied for considering continuous variable quantum teleportation. It is found that the continuous variable quantum teleportation transforms the s-parametrized phase-space function of an input state into the $(s+\ensuremath{\delta})$-parametrized phase-space function, where the parameter $\ensuremath{\delta}$ is determined by the shared quantum entanglement. It is shown from this result that the Wigner function of the teleported state is always non-negative for ${\mathcal{F}}_{c}\ensuremath{\leqslant}2∕3$ and the Glauber-Sudarshan P function non-negative for ${\mathcal{F}}_{c}\ensuremath{\leqslant}1∕2$, where Fc is the fidelity of the coherent-state teleportation. Furthermore the fidelity between input and output states is calculated when Gaussian states are teleported.