Gain tuning for continuous-variable quantum teleportation of discrete-variable states

TL;DR

This paper develops a formalism for gain-tuned continuous-variable quantum teleportation of discrete-variable states, accounting for experimental imperfections, and demonstrates how optimal gain can enhance teleportation fidelity and entanglement transfer.

Contribution

It introduces a comprehensive formalism for modeling gain-tuned CV teleportation of DV states, including experimental imperfections and optimal gain analysis.

Findings

Optimal gain improves transfer fidelity in CV teleportation.

DV entanglement can be teleported with any non-zero squeezing under certain conditions.

The formalism accurately models recent teleportation experiments.

Abstract

We present a general formalism to describe continuous-variable (CV) quantum teleportation of discrete-variable (DV) states with gain tuning, taking into account experimental imperfections. Here the teleportation output is given by independently transforming each density matrix element of the initial state. This formalism allows us to accurately model various teleportation experiments and to analyze the gain dependence of their respective figures of merit. We apply our formalism to the recent experiment of CV teleportation of qubits [S. Takeda et al., Nature 500, 315 (2013)] and investigate the optimal gain for the transfer fidelity. We also propose and model an experiment for CV teleportation of DV entanglement. It is shown that, provided the experimental losses are within a certain range, DV entanglement can be teleported for any non-zero squeezing by optimally tuning the gain.