Heralded amplification of photonic qubits

TL;DR

This paper presents a practical heralded amplification scheme for photonic qubits at telecom wavelengths, demonstrating high performance and the first heralded Fock-state qubit amplifier without post-selection, advancing quantum communication capabilities.

Contribution

It introduces a simple, stable, and integrated all-fibre scheme for heralded qubit amplification, including the first Fock-state qubit amplifier without post-selection.

Findings

High gain and fidelity achieved as a function of loss

Demonstrated first heralded Fock-state qubit amplifier without post-selection

Potential for device-independent quantum key distribution

Abstract

We demonstrate heralded qubit amplification for Time-Bin and Fock-state qubits in an all-fibre, telecom-wavelength, scheme that highlights the simplicity, the stability and potential for fully integrated photonic solutions. Exploiting high-efficiency superconducting detectors, the gain, the fidelity and the performance of the amplifier are studied as a function of loss. We also demonstrate the first heralded Fock-state qubit amplifier without post-selection. This provides a significant advance towards demonstrating Device-Independent Quantum Key Distribution as well as fundamental tests of quantum mechanics over extended distances.