On the Teleportation of Discrete Variable Qubits Via Continuous Variable Lossy Channels

TL;DR

This paper introduces a non-deterministic teleportation protocol that significantly improves the fidelity of discrete-variable qubit teleportation over lossy continuous-variable channels, enabling near-perfect teleportation even at high losses.

Contribution

It proposes a novel teleportation protocol combining Gaussian CV resources with modified Bell measurements, surpassing classical fidelity limits under high channel loss.

Findings

Achieves DV-qubit fidelity beyond classical limit up to 20 dB loss

Uses non-Gaussian operations to approach unity fidelity regardless of loss

Demonstrates orders of magnitude improvement over previous methods

Abstract

The Continuous-Variable (CV) quantum state of light allows for the teleportation of a Discrete-Variable (DV) photonic qubit. Such an operation is useful in the realm of hybrid quantum networks. However, it is known that the teleportation of a DV qubit via a Gaussian CV resource channel is severely limited under channel loss, with a teleportation fidelity beyond the classical limit unattainable for losses exceeding a small threshold of 0.5 dB. In this work, we present a new non-deterministic teleportation protocol that combines a Gaussian CV resource channel with a modified form of the Bell State Measurement that accommodates a DV-qubit fidelity beyond the classical limit for channel losses up to 20~dB. Beyond this orders of magnitude improvement, we also show how the use of non-Gaussian operations on the CV resource channel can lead to a DV-qubit fidelity approaching unity for any channel loss.