Work

Photonic quantum circuits with only synchronous directional couplers in ion-exchanged glass

Year: 2025

Type: article

Abstract: We show that photonic quantum circuits for implementing arbitrary SU(N) transformations can be made using only synchronous directional couplers. These simple elements provide both beam splitting and phase shifting so that, under a proper concatenation of such elements, unitary transformations of arbitrary dimension can be implemented. The circuits made in this way are robust and controllable, because only one type of element is used and the technology involved in their fabrication is very mature. We present several examples of original passive photonic circuits intended for quantum projective measurements and quantum state generation due to their interest in photonic quantum technology for quantum key distribution systems. Likewise, we have designed, fabricated, and characterized, on an ion-exchanged glass platform, different couplers, which form the basic elements or building blocks of these passive circuits highly compatible with optical fibres.

Source: Journal of Physics Photonics

DOI: 10.1088/2515-7647/ae142b

Authors: Jesús Liñares, Carlos Montero-Orille, Xesús Prieto-Blanco, Javier Varela-Carballo, Daniel Balado

Institutions: Universidade de Santiago de Compostela, Instituto de Tecnologías Físicas y de la Información “Leonardo Torres Quevedo”

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,700

Funder: NextGenerationEU