Experimental direct quantum communication with squeezed states

Year: 2025

Authors: Paparelle I., Mousavi F., Scazza F., Bassi A., Paris M., Zavatta A.

Autors Affiliation: PSL Res Univ, Sorbonne Univ, Coll France, Lab Kastler Brossel,CNRS,ENS, 4 Pl Jussieu, F-75252 Paris, France; Univ Trieste, Dipartimento Fis, Via Alfonso Valerio 2, I-34127 Trieste, TS, Italy; Ist Nazl Ottica, Consiglio Nazl Ric, Edificio Q2 Area Sci Pk StradaStatale 14,Km 163,5, I-34149 Basovizza, TS, Italy; Area Sci Pk Str Statale 14,Km 163, I-34149 Basovizza, TS, Italy; Univ Milan, Quantum Technol Lab, I-20133 Milan, Italy; CNR, Ist Nazl Ott, Largo Enr Fermi 6, I-50125 Florence, FI, Italy; Univ Florence, European Lab Nonlinear Spect LENS, Via Nello Carrara 1, I-50019 Sesto Fiorentino, FI, Italy.

Abstract: Quantum secure direct communication (QSDC) is an evolving quantum communication framework based on transmitting secure information directly through a quantum channel, without relying on key-based encryption such as in quantum key distribution (QKD). Optical QSDC protocols, utilizing discrete and continuous variable encodings, show great promise for future technological applications. We present the first table-top continuous-variable QSDC proof of principle, analyzing its implementation and comparing the use of coherent against squeezed light sources. A simple beam-splitter attack is analyzed by using Wyner wiretap channel theory. Our study illustrates the advantage of squeezed states over coherent ones for enhanced security and reliable communication in lossy and noisy channels. Our practical implementation, utilizing mature telecom components, could foster secure quantum metropolitan networks compatible with advanced multiplexing systems. (c) 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Journal/Review: OPTICS EXPRESS

Volume: 33 (14)      Pages from: 28917  to: 28934

More Information: Regione Autonoma Friuli Venezia Giulia (Quantum FVG) ; Ministry of Enterprises and Made in Italy (CTEMT (Casa delle Tecnologie Emergenti Matera) ) ; European Commission (QUID (Quantum Italy Deployment) No 101091408) ; Consiglio Nazionale delle Ricerche (QuONTENT) ; Ministero dell’Universita e della Ricerca (NQSTI (PE 0000023) , SERICS (PE00000014) , PRIN 2022 project RISQUE (contract n. 2022T25TR3), PON RI 2014-2020 FESR Project ARS0100734 QUANCOM, PON RI 2014-2020 (code: 33-G-15032-2) ) ; NextGenerationEU (PRIN 2022 RISQUE contract n. 2022T25TR3, SERICS (PE00000014) , NQSTI (PE0000023) , I-PHOQS Research Infrastructure (IR0000016) Integrated infrastructure initiative in Photonic and Quantum Sciences).
KeyWords: Secure Direct Communication; Key Distribution; Protocol
DOI: 10.1364/OE.538593