Hernández Martínez, OsmeryLiberal Olleta, Íñigo2022-12-282022-12-282022Osmery Hernández and Iñigo Liberal, "Generalized approach to quantum interference in lossy N-port devices via a singular value decomposition," Opt. Express 30, 31267-31286 (2022)1094-408710.1364/OE.456495https://academica-e.unavarra.es/handle/2454/44529Modeling quantum interference in the presence of dissipation is a critical aspect of quantum technologies. Including dissipation into the model of a linear device enables for assessing the detrimental impact of photon loss, as well as for studying dissipation-driven quantum state transformations. However, establishing the input-output relations characterizing quantum interference at a general lossy N-port network poses important theoretical challenges. Here, we propose a general procedure based on the singular value decomposition (SVD), which allows for the efficient calculation of the input-output relations for any arbitrary lossy linear device. In addition, we show how the SVD provides an intuitive description of the principle of operation of linear optical devices. We illustrate the applicability of our method by evaluating the input-output relations of popular reciprocal and nonreciprocal lossy linear devices, including devices with singular and nilpotent scattering matrices. Our method also enables the analysis of quantum interference in large lossy networks, as we exemplify with the study of an N-port epsilon-near-zero (ENZ) hub. We expect that our procedure will motivate future research on quantum interference in complex devices, as well as the realistic modelling of photon loss in linear lossy devices.application/pdfeng© 2022 Optica Publishing Group. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.Quantun interferenceLossy N-port devicesSingular value decomposition (SVD)info:eu-repo/semantics/article2022-12-28info:eu-repo/semantics/openAccess