Field Test of Quantum Key Distribution with High Key Creation Efficiency

TL;DR

This paper demonstrates a field test of quantum key distribution using a specially developed single-photon source, achieving a near-perfect key creation efficiency of 97%, which significantly improves practical QKD performance.

Contribution

Developed a miniature 1550-nm single-photon source with controllable waveforms for high-efficiency differential-phase-shift QKD, achieving 97% key creation efficiency in a field test.

Findings

Achieved 97% key creation efficiency in field QKD test.

Demonstrated practical benefits of narrowband single photons with controllable waveforms.

Showed potential for improved real-world quantum communication security.

Abstract

Quantumkey distribution (QKD) promises unconditional security for communication. However, the random choices of the measurement basis in QKD usually result in low key creation efficiency. This drawback is overcome in the differential-phase-shift QKD, provided that each photon can be prepared in a large number of time bins with a proper waveform. In this work we develop a miniature 1550-nm single-photon source to generate narrowband single photon in 50 time bins with a nearly optimal waveform for achieving unity key creation efficiency. By utilizing these single photons in the field test, we demonstrate the differential-phase-shift QKD with a key creation efficiency of 97%. Our work shows that the practical QKD can benefit from the narrowband single photons with controllable waveforms.