Practical quantum teleportation with finite-energy codebooks

TL;DR

This paper analyzes practical microwave quantum teleportation using continuous-variable states, focusing on the effects of noise, finite codebooks, and security, demonstrating feasibility for secure quantum communication networks.

Contribution

It introduces a detailed analysis of feedforward imperfections, finite codebook effects, and security thresholds, advancing practical microwave quantum teleportation protocols.

Findings

Feedforward noise can be corrected with appropriate gain.

Finite codebooks alter no-cloning security thresholds.

Secure fidelity thresholds can differ significantly from traditional limits.

Abstract

Quantum communication exploits non-classical correlations to achieve efficient and unconditionally secure exchange of information. In particular, the quantum teleportation protocol allows for a deterministic and secure transfer of unknown quantum states by using pre-shared quantum entanglement and classical feedforward communication. Quantum teleportation in the microwave regime provides an important tool for high-fidelity remote quantum operations, enabling distributed quantum computing with superconducting circuits and potentially facilitating short-range, open-air microwave quantum communication. In this context, we consider practical application scenarios for the microwave analog quantum teleportation protocol based on continuous-variable states. We theoretically analyze the effect of feedforward losses and noise on teleportation fidelities of coherent states and show that these imperfections can be fully corrected by an appropriate feedforward gain. Furthermore, we consider quantum teleportation with finite-size codebooks and derive modified no-cloning thresholds as a function of the codebook configuration. Finally, we analyze the security of quantum teleportation under public channel attacks and demonstrate that the corresponding secure fidelity thresholds may drastically differ from the conventional no-cloning values. Our results contribute to the general development of quantum communication protocols and, in particular, illustrate the feasibility of using quantum teleportation in realistic microwave networks for robust and unconditionally secure communication.