[{"status":"public","publisher":"Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften","_id":"58519","user_id":"16199","volume":9,"citation":{"bibtex":"@article{Kopylov_Meier_Sharapova_2025, title={Theory of Multimode Squeezed Light Generation in Lossy Media}, volume={9}, DOI={<a href=\"https://doi.org/10.22331/q-2025-02-04-1621\">10.22331/q-2025-02-04-1621</a>}, number={1621}, journal={Quantum}, publisher={Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften}, author={Kopylov, Denis A. and Meier, Torsten and Sharapova, Polina R.}, year={2025} }","ama":"Kopylov DA, Meier T, Sharapova PR. Theory of Multimode Squeezed Light Generation in Lossy Media. <i>Quantum</i>. 2025;9. doi:<a href=\"https://doi.org/10.22331/q-2025-02-04-1621\">10.22331/q-2025-02-04-1621</a>","mla":"Kopylov, Denis A., et al. “Theory of Multimode Squeezed Light Generation in Lossy Media.” <i>Quantum</i>, vol. 9, 1621, Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften, 2025, doi:<a href=\"https://doi.org/10.22331/q-2025-02-04-1621\">10.22331/q-2025-02-04-1621</a>.","chicago":"Kopylov, Denis A., Torsten Meier, and Polina R. Sharapova. “Theory of Multimode Squeezed Light Generation in Lossy Media.” <i>Quantum</i> 9 (2025). <a href=\"https://doi.org/10.22331/q-2025-02-04-1621\">https://doi.org/10.22331/q-2025-02-04-1621</a>.","short":"D.A. Kopylov, T. Meier, P.R. Sharapova, Quantum 9 (2025).","ieee":"D. A. Kopylov, T. Meier, and P. R. Sharapova, “Theory of Multimode Squeezed Light Generation in Lossy Media,” <i>Quantum</i>, vol. 9, Art. no. 1621, 2025, doi: <a href=\"https://doi.org/10.22331/q-2025-02-04-1621\">10.22331/q-2025-02-04-1621</a>.","apa":"Kopylov, D. A., Meier, T., &#38; Sharapova, P. R. (2025). Theory of Multimode Squeezed Light Generation in Lossy Media. <i>Quantum</i>, <i>9</i>, Article 1621. <a href=\"https://doi.org/10.22331/q-2025-02-04-1621\">https://doi.org/10.22331/q-2025-02-04-1621</a>"},"project":[{"_id":"266","name":"PhoQC: PhoQC: Photonisches Quantencomputing"},{"name":"Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"}],"year":"2025","title":"Theory of Multimode Squeezed Light Generation in Lossy Media","author":[{"last_name":"Kopylov","first_name":"Denis A.","full_name":"Kopylov, Denis A."},{"last_name":"Meier","orcid":"0000-0001-8864-2072","first_name":"Torsten","full_name":"Meier, Torsten","id":"344"},{"id":"60286","last_name":"Sharapova","first_name":"Polina R.","full_name":"Sharapova, Polina R."}],"publication_identifier":{"issn":["2521-327X"]},"publication_status":"published","date_updated":"2025-09-18T13:22:26Z","intvolume":"         9","article_number":"1621","language":[{"iso":"eng"}],"doi":"10.22331/q-2025-02-04-1621","publication":"Quantum","abstract":[{"lang":"eng","text":"<jats:p>A unified theoretical approach to describe the properties of multimode squeezed light generated in a lossy medium is presented. This approach is valid for Markovian environments and includes both a model of discrete losses based on the beamsplitter approach and a generalized continuous loss model based on the spatial Langevin equation. For an important class of Gaussian states, we derive master equations for the second-order correlation functions and illustrate their solution for both frequency-independent and frequency-dependent losses. Studying the mode structure, we demonstrate that in a lossy environment no broadband basis without quadrature correlations between the different broadband modes exists. Therefore, various techniques and strategies to introduce broadband modes can be considered. We show that the Mercer expansion and the Williamson-Euler decomposition do not provide modes in which the maximal squeezing contained in the system can be measured. In turn, we find a new broadband basis that maximizes squeezing in the lossy system and present an algorithm to construct it.</jats:p>"}],"date_created":"2025-02-05T12:57:37Z","type":"journal_article","department":[{"_id":"15"},{"_id":"569"},{"_id":"170"},{"_id":"293"},{"_id":"35"},{"_id":"230"},{"_id":"623"},{"_id":"27"}]},{"volume":5,"user_id":"71541","_id":"29780","publisher":"Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften","status":"public","citation":{"ama":"Broadbent A, Gharibian S, Zhou H-S. Towards Quantum One-Time Memories from Stateless Hardware. <i>Quantum</i>. 2021;5. doi:<a href=\"https://doi.org/10.22331/q-2021-04-08-429\">10.22331/q-2021-04-08-429</a>","bibtex":"@article{Broadbent_Gharibian_Zhou_2021, title={Towards Quantum One-Time Memories from Stateless Hardware}, volume={5}, DOI={<a href=\"https://doi.org/10.22331/q-2021-04-08-429\">10.22331/q-2021-04-08-429</a>}, number={429}, journal={Quantum}, publisher={Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften}, author={Broadbent, Anne and Gharibian, Sevag and Zhou, Hong-Sheng}, year={2021} }","mla":"Broadbent, Anne, et al. “Towards Quantum One-Time Memories from Stateless Hardware.” <i>Quantum</i>, vol. 5, 429, Verein zur Forderung des Open Access Publizierens in den Quantenwissenschaften, 2021, doi:<a href=\"https://doi.org/10.22331/q-2021-04-08-429\">10.22331/q-2021-04-08-429</a>.","chicago":"Broadbent, Anne, Sevag Gharibian, and Hong-Sheng Zhou. “Towards Quantum One-Time Memories from Stateless Hardware.” <i>Quantum</i> 5 (2021). <a href=\"https://doi.org/10.22331/q-2021-04-08-429\">https://doi.org/10.22331/q-2021-04-08-429</a>.","short":"A. Broadbent, S. Gharibian, H.-S. Zhou, Quantum 5 (2021).","apa":"Broadbent, A., Gharibian, S., &#38; Zhou, H.-S. (2021). Towards Quantum One-Time Memories from Stateless Hardware. <i>Quantum</i>, <i>5</i>, Article 429. <a href=\"https://doi.org/10.22331/q-2021-04-08-429\">https://doi.org/10.22331/q-2021-04-08-429</a>","ieee":"A. Broadbent, S. Gharibian, and H.-S. Zhou, “Towards Quantum One-Time Memories from Stateless Hardware,” <i>Quantum</i>, vol. 5, Art. no. 429, 2021, doi: <a href=\"https://doi.org/10.22331/q-2021-04-08-429\">10.22331/q-2021-04-08-429</a>."},"doi":"10.22331/q-2021-04-08-429","language":[{"iso":"eng"}],"article_number":"429","intvolume":"         5","publication_status":"published","date_updated":"2023-02-28T11:07:47Z","author":[{"last_name":"Broadbent","first_name":"Anne","full_name":"Broadbent, Anne"},{"id":"71541","full_name":"Gharibian, Sevag","last_name":"Gharibian","orcid":"0000-0002-9992-3379","first_name":"Sevag"},{"full_name":"Zhou, Hong-Sheng","last_name":"Zhou","first_name":"Hong-Sheng"}],"publication_identifier":{"issn":["2521-327X"]},"title":"Towards Quantum One-Time Memories from Stateless Hardware","year":"2021","department":[{"_id":"623"},{"_id":"7"}],"type":"journal_article","keyword":["Physics and Astronomy (miscellaneous)","Atomic and Molecular Physics","and Optics"],"date_created":"2022-02-08T10:59:00Z","abstract":[{"text":"<jats:p>A central tenet of theoretical cryptography is the study of the minimal assumptions required to implement a given cryptographic primitive. One such primitive is the one-time memory (OTM), introduced by Goldwasser, Kalai, and Rothblum [CRYPTO 2008], which is a classical functionality modeled after a non-interactive 1-out-of-2 oblivious transfer, and which is complete for one-time classical and quantum programs. It is known that secure OTMs do not exist in the standard model in both the classical and quantum settings. Here, we propose a scheme for using quantum information, together with the assumption of stateless (<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mi>i</mml:mi><mml:mo>.</mml:mo><mml:mi>e</mml:mi><mml:mo>.</mml:mo></mml:math>, reusable) hardware tokens, to build statistically secure OTMs. Via the semidefinite programming-based quantum games framework of Gutoski and Watrous [STOC 2007], we prove security for a malicious receiver making at most 0.114<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mi>n</mml:mi></mml:math> adaptive queries to the token (for <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mi>n</mml:mi></mml:math> the key size), in the quantum universal composability framework, but leave open the question of security against a polynomial amount of queries. Compared to alternative schemes derived from the literature on quantum money, our scheme is technologically simple since it is of the \"prepare-and-measure\" type. We also give two impossibility results showing certain assumptions in our scheme cannot be relaxed.</jats:p>","lang":"eng"}],"publication":"Quantum"},{"publication_identifier":{"issn":["2521-327X"]},"author":[{"id":"65609","full_name":"Ferreri, Alessandro","first_name":"Alessandro","last_name":"Ferreri"},{"id":"55095","full_name":"Santandrea, Matteo","orcid":"0000-0001-5718-358X","first_name":"Matteo","last_name":"Santandrea"},{"full_name":"Stefszky, Michael","first_name":"Michael","last_name":"Stefszky","id":"42777"},{"full_name":"Luo, Kai Hong","first_name":"Kai Hong","last_name":"Luo","orcid":"0000-0003-1008-4976","id":"36389"},{"first_name":"Harald","last_name":"Herrmann","full_name":"Herrmann, Harald","id":"216"},{"first_name":"Christine","last_name":"Silberhorn","full_name":"Silberhorn, Christine","id":"26263"},{"first_name":"Polina R.","last_name":"Sharapova","full_name":"Sharapova, Polina R.","id":"60286"}],"title":"Spectrally multimode integrated SU(1,1) interferometer","status":"public","year":"2021","publication_status":"published","date_updated":"2026-01-16T10:22:10Z","language":[{"iso":"eng"}],"_id":"26077","article_number":"461","user_id":"42777","doi":"10.22331/q-2021-05-27-461","citation":{"chicago":"Ferreri, Alessandro, Matteo Santandrea, Michael Stefszky, Kai Hong Luo, Harald Herrmann, Christine Silberhorn, and Polina R. Sharapova. “Spectrally Multimode Integrated SU(1,1) Interferometer.” <i>Quantum</i>, 2021. <a href=\"https://doi.org/10.22331/q-2021-05-27-461\">https://doi.org/10.22331/q-2021-05-27-461</a>.","short":"A. Ferreri, M. Santandrea, M. Stefszky, K.H. Luo, H. Herrmann, C. Silberhorn, P.R. Sharapova, Quantum (2021).","apa":"Ferreri, A., Santandrea, M., Stefszky, M., Luo, K. H., Herrmann, H., Silberhorn, C., &#38; Sharapova, P. R. (2021). Spectrally multimode integrated SU(1,1) interferometer. <i>Quantum</i>, Article 461. <a href=\"https://doi.org/10.22331/q-2021-05-27-461\">https://doi.org/10.22331/q-2021-05-27-461</a>","ieee":"A. Ferreri <i>et al.</i>, “Spectrally multimode integrated SU(1,1) interferometer,” <i>Quantum</i>, Art. no. 461, 2021, doi: <a href=\"https://doi.org/10.22331/q-2021-05-27-461\">10.22331/q-2021-05-27-461</a>.","ama":"Ferreri A, Santandrea M, Stefszky M, et al. Spectrally multimode integrated SU(1,1) interferometer. <i>Quantum</i>. Published online 2021. doi:<a href=\"https://doi.org/10.22331/q-2021-05-27-461\">10.22331/q-2021-05-27-461</a>","bibtex":"@article{Ferreri_Santandrea_Stefszky_Luo_Herrmann_Silberhorn_Sharapova_2021, title={Spectrally multimode integrated SU(1,1) interferometer}, DOI={<a href=\"https://doi.org/10.22331/q-2021-05-27-461\">10.22331/q-2021-05-27-461</a>}, number={461}, journal={Quantum}, author={Ferreri, Alessandro and Santandrea, Matteo and Stefszky, Michael and Luo, Kai Hong and Herrmann, Harald and Silberhorn, Christine and Sharapova, Polina R.}, year={2021} }","mla":"Ferreri, Alessandro, et al. “Spectrally Multimode Integrated SU(1,1) Interferometer.” <i>Quantum</i>, 461, 2021, doi:<a href=\"https://doi.org/10.22331/q-2021-05-27-461\">10.22331/q-2021-05-27-461</a>."},"publication":"Quantum","project":[{"_id":"56","name":"TRR 142 - C: TRR 142 - Project Area C"}],"abstract":[{"lang":"eng","text":"<jats:p>Nonlinear SU(1,1) interferometers are fruitful and promising tools for spectral engineering and precise measurements with phase sensitivity below the classical bound. Such interferometers have been successfully realized in bulk and fiber-based configurations. However, rapidly developing integrated technologies provide higher efficiencies, smaller footprints, and pave the way to quantum-enhanced on-chip interferometry. In this work, we theoretically realised an integrated architecture of the multimode SU(1,1) interferometer which can be applied to various integrated platforms. The presented interferometer includes a polarization converter between two photon sources and utilizes a continuous-wave (CW) pump. Based on the potassium titanyl phosphate (KTP) platform, we show that this configuration results in almost perfect destructive interference at the output and supersensitivity regions below the classical limit. In addition, we discuss the fundamental difference between single-mode and highly multimode SU(1,1) interferometers in the properties of phase sensitivity and its limits. Finally, we explore how to improve the phase sensitivity by filtering the output radiation and using different seeding states in different modes with various detection strategies.</jats:p>"}],"date_created":"2021-10-12T08:46:46Z","department":[{"_id":"15"},{"_id":"288"}],"type":"journal_article"},{"article_number":"343","_id":"26290","language":[{"iso":"eng"}],"user_id":"16199","doi":"10.22331/q-2020-10-15-343","year":"2020","title":"Probing nonclassicality with matrices of phase-space distributions","status":"public","author":[{"full_name":"Bohmann, Martin","first_name":"Martin","last_name":"Bohmann"},{"full_name":"Agudelo, Elizabeth","last_name":"Agudelo","first_name":"Elizabeth"},{"orcid":"0000-0002-5844-3205","last_name":"Sperling","first_name":"Jan","full_name":"Sperling, Jan","id":"75127"}],"publication_identifier":{"issn":["2521-327X"]},"publication_status":"published","date_updated":"2023-04-20T15:12:58Z","date_created":"2021-10-15T16:10:46Z","type":"journal_article","department":[{"_id":"15"},{"_id":"170"},{"_id":"706"},{"_id":"35"}],"publication":"Quantum","citation":{"short":"M. Bohmann, E. Agudelo, J. Sperling, Quantum (2020).","chicago":"Bohmann, Martin, Elizabeth Agudelo, and Jan Sperling. “Probing Nonclassicality with Matrices of Phase-Space Distributions.” <i>Quantum</i>, 2020. <a href=\"https://doi.org/10.22331/q-2020-10-15-343\">https://doi.org/10.22331/q-2020-10-15-343</a>.","ieee":"M. Bohmann, E. Agudelo, and J. Sperling, “Probing nonclassicality with matrices of phase-space distributions,” <i>Quantum</i>, Art. no. 343, 2020, doi: <a href=\"https://doi.org/10.22331/q-2020-10-15-343\">10.22331/q-2020-10-15-343</a>.","apa":"Bohmann, M., Agudelo, E., &#38; Sperling, J. (2020). Probing nonclassicality with matrices of phase-space distributions. <i>Quantum</i>, Article 343. <a href=\"https://doi.org/10.22331/q-2020-10-15-343\">https://doi.org/10.22331/q-2020-10-15-343</a>","bibtex":"@article{Bohmann_Agudelo_Sperling_2020, title={Probing nonclassicality with matrices of phase-space distributions}, DOI={<a href=\"https://doi.org/10.22331/q-2020-10-15-343\">10.22331/q-2020-10-15-343</a>}, number={343}, journal={Quantum}, author={Bohmann, Martin and Agudelo, Elizabeth and Sperling, Jan}, year={2020} }","ama":"Bohmann M, Agudelo E, Sperling J. Probing nonclassicality with matrices of phase-space distributions. <i>Quantum</i>. Published online 2020. doi:<a href=\"https://doi.org/10.22331/q-2020-10-15-343\">10.22331/q-2020-10-15-343</a>","mla":"Bohmann, Martin, et al. “Probing Nonclassicality with Matrices of Phase-Space Distributions.” <i>Quantum</i>, 343, 2020, doi:<a href=\"https://doi.org/10.22331/q-2020-10-15-343\">10.22331/q-2020-10-15-343</a>."},"abstract":[{"text":"<jats:p>We devise a method to certify nonclassical features via correlations of phase-space distributions by unifying the notions of quasiprobabilities and matrices of correlation functions. Our approach complements and extends recent results that were based on Chebyshev's integral inequality \\cite{BA19}. The method developed here correlates arbitrary phase-space functions at arbitrary points in phase space, including multimode scenarios and higher-order correlations. Furthermore, our approach provides necessary and sufficient nonclassicality criteria, applies to phase-space functions beyond <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"><mml:mi>s</mml:mi></mml:math>-parametrized ones, and is accessible in experiments. To demonstrate the power of our technique, the quantum characteristics of discrete- and continuous-variable, single- and multimode, as well as pure and mixed states are certified only employing second-order correlations and Husimi functions, which always resemble a classical probability distribution. Moreover, nonlinear generalizations of our approach are studied. Therefore, a versatile and broadly applicable framework is devised to uncover quantum properties in terms of matrices of phase-space distributions.</jats:p>","lang":"eng"}]}]