Continuous-variable teleportation: a new look

TL;DR

This paper revisits continuous-variable quantum teleportation, analyzing the noise and fidelity of the process using Gaussian states, and provides insights into the properties of the distorting field affecting teleportation quality.

Contribution

It offers a detailed analysis of the Gaussian distorting field in continuous-variable teleportation and examines how the resource state's properties influence teleportation fidelity.

Findings

Teleportation is inherently noisy, affecting the input state.

The properties of the distorting field depend on the EPR operator statistics.

Fidelity of teleporting a coherent state varies with the resource state used.

Abstract

In contrast to discrete-variable teleportation, a quantum state is imperfectly transferred from a sender to a remote receiver in a continuous-variable setting. We recall the ingenious scheme proposed by Braunstein and Kimble for teleporting a one-mode state of the quantum radiation field. By analyzing this protocol, we have previously proven the factorization of the characteristic function of the output state. This indicates that teleportation is a noisy process that alters, to some extent, the input state. Teleportation with a two-mode Gaussian EPR state can be described in terms of the superposition of a distorting field with the input one. Here we analyze the one-mode Gaussian distorting-field state. Some of its most important properties are determined by the statistics of a positive EPR operator in the two-mode Gaussian resource state. We finally examine the fidelity of teleportation of a coherent state when using an arbitrary resource state.