High-rate intercity quantum key distribution with a semiconductor single-photon source

verfasst von
Jingzhong Yang, Zenghui Jiang, Frederik Benthin, Joscha Hanel, Tom Fandrich, Raphael Joos, Stephanie Bauer, Sascha Kolatschek, Ali Hreibi, Eddy Patrick Rugeramigabo, Michael Jetter, Simone Luca Portalupi, Michael Zopf, Peter Michler, Stefan Kück, Fei Ding
Abstract

Quantum key distribution (QKD) enables the transmission of information that is secure against general attacks by eavesdroppers. The use of on-demand quantum light sources in QKD protocols is expected to help improve security and maximum tolerable loss. Semiconductor quantum dots (QDs) are a promising building block for quantum communication applications because of the deterministic emission of single photons with high brightness and low multiphoton contribution. Here we report on the first intercity QKD experiment using a bright deterministic single photon source. A BB84 protocol based on polarisation encoding is realised using the high-rate single photons in the telecommunication C-band emitted from a semiconductor QD embedded in a circular Bragg grating structure. Utilising the 79 km long link with 25.49 dB loss (equivalent to 130 km for the direct-connected optical fibre) between the German cities of Hannover and Braunschweig, a record-high secret key bits per pulse of 4.8 × 10−5 with an average quantum bit error ratio of ~ 0.65% are demonstrated. An asymptotic maximum tolerable loss of 28.11 dB is found, corresponding to a length of 144 km of standard telecommunication fibre. Deterministic semiconductor sources therefore challenge state-of-the-art QKD protocols and have the potential to excel in measurement device independent protocols and quantum repeater applications.

Organisationseinheit(en)
Institut für Festkörperphysik
Abt. Atomare und molekulare Strukturen (ATMOS)
Laboratorium für Nano- und Quantenengineering
QuantumFrontiers
Externe Organisation(en)
Universität Stuttgart
Physikalisch-Technische Bundesanstalt (PTB)
Typ
Artikel
Journal
Light: Science and Applications
Band
13
Anzahl der Seiten
10
ISSN
2095-5545
Publikationsdatum
12.2024
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Elektronische, optische und magnetische Materialien, Atom- und Molekularphysik sowie Optik
Elektronische Version(en)
https://doi.org/10.1038/s41377-024-01488-0 (Zugang: Offen)