--- _id: '61523' abstract: - lang: eng text: AbstractMetasurface holography offers a powerful approach for manipulating wavefronts at the nano and micro scale. Extensive research has been conducted to enhance the multiplexing capacity for diverse wavefronts. However, the independence of multiplexed channels is fundamentally restricted in techniques using single‐layer metasurfaces, resulting in unavoidable crosstalk and the need for post‐filtering of the output wavefronts. Here, a universal wavefront multiplexing concept is presented based on non‐injective transformation. By employing joint optimization on two metasurfaces, different channels can be independently designed without any constraints on the output wavefronts. To validate this approach, ultra‐compact orbital angular momentum (OAM) sorters are designed. In these experiments, the output beams from different channels can be independently mapped to 2D positions with high fineness. In another application of wavefront‐multiplexed holography, 10‐channel multiplexing is experimentally achieved with minimal crosstalk and without the need for post‐processing. These results demonstrate the independence between channels enabled by the non‐injective transformation in the method. The precise wavefront control and high multiplexing capacity underscore its potential for scalable wavefront manipulation devices. article_number: e11823 article_type: original author: - first_name: Xiao full_name: Jin, Xiao last_name: Jin - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 citation: ama: Jin X, Zentgraf T. Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation. Advanced Materials. 2026;38. doi:10.1002/adma.202511823 apa: Jin, X., & Zentgraf, T. (2026). Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation. Advanced Materials, 38, Article e11823. https://doi.org/10.1002/adma.202511823 bibtex: '@article{Jin_Zentgraf_2026, title={Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation}, volume={38}, DOI={10.1002/adma.202511823}, number={e11823}, journal={Advanced Materials}, publisher={Wiley}, author={Jin, Xiao and Zentgraf, Thomas}, year={2026} }' chicago: Jin, Xiao, and Thomas Zentgraf. “Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation.” Advanced Materials 38 (2026). https://doi.org/10.1002/adma.202511823. ieee: 'X. Jin and T. Zentgraf, “Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation,” Advanced Materials, vol. 38, Art. no. e11823, 2026, doi: 10.1002/adma.202511823.' mla: Jin, Xiao, and Thomas Zentgraf. “Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation.” Advanced Materials, vol. 38, e11823, Wiley, 2026, doi:10.1002/adma.202511823. short: X. Jin, T. Zentgraf, Advanced Materials 38 (2026). date_created: 2025-10-06T05:42:21Z date_updated: 2026-03-10T08:32:37Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '623' doi: 10.1002/adma.202511823 intvolume: ' 38' language: - iso: eng main_file_link: - open_access: '1' url: https://advanced.onlinelibrary.wiley.com/doi/10.1002/adma.202511823 oa: '1' project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: TRR 142 - Project Area A - _id: '55' name: TRR 142 - Project Area B - _id: '65' name: 'TRR 142; TP A08: Nichtlineare Kopplung von Zwischenschicht-Exzitonen in van der Waals-Heterostrukturen an plasmonische und dielektrische Nanokavitäten' - _id: '170' name: 'TRR 142; TP B09: Effiziente Erzeugung mit maßgeschneiderter optischer Phaselage der zweiten Harmonischen mittels Quasi-gebundener Zustände in GaAs Metaoberflächen' publication: Advanced Materials publication_identifier: issn: - 0935-9648 - 1521-4095 publication_status: published publisher: Wiley quality_controlled: '1' status: public title: Independent Wavefront Multiplexing with Metasurfaces via Non‐Injective Transformation type: journal_article user_id: '30525' volume: 38 year: '2026' ... --- _id: '64877' author: - first_name: Behnood full_name: Taheri, Behnood last_name: Taheri - first_name: Denis full_name: Kopylov, Denis id: '98502' last_name: Kopylov - first_name: Manfred full_name: Hammer, Manfred id: '48077' last_name: Hammer orcid: 0000-0002-6331-9348 - first_name: Torsten full_name: Meier, Torsten id: '344' last_name: Meier orcid: 0000-0001-8864-2072 - first_name: Jens full_name: Förstner, Jens id: '158' last_name: Förstner orcid: 0000-0001-7059-9862 - first_name: Polina R. full_name: Sharapova, Polina R. id: '60286' last_name: Sharapova citation: ama: Taheri B, Kopylov D, Hammer M, Meier T, Förstner J, Sharapova PR. Gain-induced spectral non-degeneracy in type-II parametric down-conversion. arXiv. Published online 2026. doi:10.48550/ARXIV.2603.01656 apa: Taheri, B., Kopylov, D., Hammer, M., Meier, T., Förstner, J., & Sharapova, P. R. (2026). Gain-induced spectral non-degeneracy in type-II parametric down-conversion. ArXiv. https://doi.org/10.48550/ARXIV.2603.01656 bibtex: '@article{Taheri_Kopylov_Hammer_Meier_Förstner_Sharapova_2026, title={Gain-induced spectral non-degeneracy in type-II parametric down-conversion}, DOI={10.48550/ARXIV.2603.01656}, journal={arXiv}, author={Taheri, Behnood and Kopylov, Denis and Hammer, Manfred and Meier, Torsten and Förstner, Jens and Sharapova, Polina R.}, year={2026} }' chicago: Taheri, Behnood, Denis Kopylov, Manfred Hammer, Torsten Meier, Jens Förstner, and Polina R. Sharapova. “Gain-Induced Spectral Non-Degeneracy in Type-II Parametric down-Conversion.” ArXiv, 2026. https://doi.org/10.48550/ARXIV.2603.01656. ieee: 'B. Taheri, D. Kopylov, M. Hammer, T. Meier, J. Förstner, and P. R. Sharapova, “Gain-induced spectral non-degeneracy in type-II parametric down-conversion,” arXiv, 2026, doi: 10.48550/ARXIV.2603.01656.' mla: Taheri, Behnood, et al. “Gain-Induced Spectral Non-Degeneracy in Type-II Parametric down-Conversion.” ArXiv, 2026, doi:10.48550/ARXIV.2603.01656. short: B. Taheri, D. Kopylov, M. Hammer, T. Meier, J. Förstner, P.R. Sharapova, ArXiv (2026). date_created: 2026-03-10T15:37:22Z date_updated: 2026-03-10T15:41:18Z department: - _id: '15' - _id: '569' - _id: '170' - _id: '293' - _id: '35' - _id: '34' - _id: '61' - _id: '230' - _id: '623' - _id: '429' doi: 10.48550/ARXIV.2603.01656 language: - iso: eng project: - _id: '168' name: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*) - _id: '56' name: TRR 142 - Project Area C - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' publication: arXiv status: public title: Gain-induced spectral non-degeneracy in type-II parametric down-conversion type: journal_article user_id: '16199' year: '2026' ... --- _id: '60022' author: - first_name: Michael full_name: Brauckmann, Michael last_name: Brauckmann - first_name: Emmanuel full_name: Narvaez Castaneda, Emmanuel last_name: Narvaez Castaneda - first_name: Dustin full_name: Siebert, Dustin last_name: Siebert - first_name: Benjamin full_name: Brecht, Benjamin id: '27150' last_name: Brecht orcid: '0000-0003-4140-0556 ' - first_name: Jens full_name: Förstner, Jens id: '158' last_name: Förstner orcid: 0000-0001-7059-9862 - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 citation: ama: 'Brauckmann M, Narvaez Castaneda E, Siebert D, Brecht B, Förstner J, Zentgraf T. Enhancement Of Light-matter Interaction In Topological Waveguides And Resonators. In: Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics. ; 2025.' apa: Brauckmann, M., Narvaez Castaneda, E., Siebert, D., Brecht, B., Förstner, J., & Zentgraf, T. (2025). Enhancement Of Light-matter Interaction In Topological Waveguides And Resonators. Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics. META 2025 - The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Malaga, Spain. bibtex: '@inproceedings{Brauckmann_Narvaez Castaneda_Siebert_Brecht_Förstner_Zentgraf_2025, title={Enhancement Of Light-matter Interaction In Topological Waveguides And Resonators}, booktitle={Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics}, author={Brauckmann, Michael and Narvaez Castaneda, Emmanuel and Siebert, Dustin and Brecht, Benjamin and Förstner, Jens and Zentgraf, Thomas}, year={2025} }' chicago: Brauckmann, Michael, Emmanuel Narvaez Castaneda, Dustin Siebert, Benjamin Brecht, Jens Förstner, and Thomas Zentgraf. “Enhancement Of Light-Matter Interaction In Topological Waveguides And Resonators.” In Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2025. ieee: M. Brauckmann, E. Narvaez Castaneda, D. Siebert, B. Brecht, J. Förstner, and T. Zentgraf, “Enhancement Of Light-matter Interaction In Topological Waveguides And Resonators,” presented at the META 2025 - The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Malaga, Spain, 2025. mla: Brauckmann, Michael, et al. “Enhancement Of Light-Matter Interaction In Topological Waveguides And Resonators.” Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2025. short: 'M. Brauckmann, E. Narvaez Castaneda, D. Siebert, B. Brecht, J. Förstner, T. Zentgraf, in: Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2025.' conference: end_date: 2025-07-25 location: Malaga, Spain name: META 2025 - The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics start_date: 2025-07-22 date_created: 2025-05-23T06:10:53Z date_updated: 2025-05-23T06:11:20Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '623' language: - iso: eng project: - _id: '53' grant_number: '231447078' name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: 'TRR 142 - A: TRR 142 - Project Area A' - _id: '164' grant_number: '231447078' name: 'TRR 142 - A09: TRR 142 - Erzeugung von Drei-Photonen-Zuständen mit On-Chip Pumplichtunterdrückung in topologischen Wellenleitern (A09*)' publication: Proceedings of The 15th International Conference on Metamaterials, Photonic Crystals and Plasmonics status: public title: Enhancement Of Light-matter Interaction In Topological Waveguides And Resonators type: conference user_id: '30525' year: '2025' ... --- _id: '63744' abstract: - lang: eng text: Orbital angular momentum (OAM) modes are an important resource used in various branches of quantum science and technology due to their unique helical structure and countably infinite basis. Generating light that simultaneously carries high-order orbital angular momenta and exhibits quantum correlations is a challenging task. In this work, we present a theoretical approach to the generation of correlated Schmidt modes carrying OAM via parametric down-conversion (PDC) in cascaded nonlinear systems (nonlinear interferometers) pumped by Laguerre–Gaussian beams. We demonstrate how the number of generated modes and their population can be controlled by varying the pump parameters, the gain of the PDC process, and the distance between the crystals. We investigate the angular displacement measurement uncertainty of these interferometers and demonstrate that it can overcome the classical shot noise limit. article_number: '016112' article_type: original author: - first_name: Dennis full_name: Scharwald, Dennis id: '55907' last_name: Scharwald orcid: 0009-0007-5654-5412 - first_name: Lucas full_name: Gehse, Lucas last_name: Gehse - first_name: Polina full_name: Sharapova, Polina id: '60286' last_name: Sharapova citation: ama: Scharwald D, Gehse L, Sharapova P. Schmidt modes carrying orbital angular momentum generated by cascaded systems pumped with Laguerre–Gaussian beams. APL Photonics. 2025;10(1). doi:10.1063/5.0229802 apa: Scharwald, D., Gehse, L., & Sharapova, P. (2025). Schmidt modes carrying orbital angular momentum generated by cascaded systems pumped with Laguerre–Gaussian beams. APL Photonics, 10(1), Article 016112. https://doi.org/10.1063/5.0229802 bibtex: '@article{Scharwald_Gehse_Sharapova_2025, title={Schmidt modes carrying orbital angular momentum generated by cascaded systems pumped with Laguerre–Gaussian beams}, volume={10}, DOI={10.1063/5.0229802}, number={1016112}, journal={APL Photonics}, publisher={AIP Publishing}, author={Scharwald, Dennis and Gehse, Lucas and Sharapova, Polina}, year={2025} }' chicago: Scharwald, Dennis, Lucas Gehse, and Polina Sharapova. “Schmidt Modes Carrying Orbital Angular Momentum Generated by Cascaded Systems Pumped with Laguerre–Gaussian Beams.” APL Photonics 10, no. 1 (2025). https://doi.org/10.1063/5.0229802. ieee: 'D. Scharwald, L. Gehse, and P. Sharapova, “Schmidt modes carrying orbital angular momentum generated by cascaded systems pumped with Laguerre–Gaussian beams,” APL Photonics, vol. 10, no. 1, Art. no. 016112, 2025, doi: 10.1063/5.0229802.' mla: Scharwald, Dennis, et al. “Schmidt Modes Carrying Orbital Angular Momentum Generated by Cascaded Systems Pumped with Laguerre–Gaussian Beams.” APL Photonics, vol. 10, no. 1, 016112, AIP Publishing, 2025, doi:10.1063/5.0229802. short: D. Scharwald, L. Gehse, P. Sharapova, APL Photonics 10 (2025). date_created: 2026-01-26T15:48:54Z date_updated: 2026-02-01T13:19:20Z department: - _id: '15' - _id: '569' - _id: '170' - _id: '35' - _id: '429' doi: 10.1063/5.0229802 intvolume: ' 10' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://pubs.aip.org/aip/app/article-pdf/doi/10.1063/5.0229802/20352749/016112_1_5.0229802.pdf oa: '1' project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '56' name: TRR 142 - Project Area C - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: APL Photonics publication_identifier: issn: - 2378-0967 publication_status: published publisher: AIP Publishing status: public title: Schmidt modes carrying orbital angular momentum generated by cascaded systems pumped with Laguerre–Gaussian beams type: journal_article user_id: '55907' volume: 10 year: '2025' ... --- _id: '63745' abstract: - lang: eng text: Multimode squeezed light is an increasingly popular tool in photonic quantum technologies, including sensing, imaging, and computation. Meanwhile, the existing methods of its characterization are technically complicated, which reduces the level of squeezing, and mostly deal with a single mode at a time. Here, for the first time, to the best of our knowledge, we employ optical parametric amplification to characterize multiple squeezing eigenmodes simultaneously. We retrieve the shapes and squeezing degrees of all modes at once through direct detection followed by modal decomposition. This method is tolerant to inefficient detection and does not require a local oscillator. For a spectrally and spatially multimode squeezed vacuum, we characterize eight strongest spatial modes, obtaining squeezing and anti-squeezing values of up to −5.2 ± 0.2 dB and 8.6 ± 0.3 dB, respectively, despite the 50% detection loss. This work, being the first exploration of an optical parametric amplifier’s multimode capability for squeezing detection, paves the way for the real-time detection of multimode squeezing. article_number: '36' article_type: original author: - first_name: Ismail full_name: Barakat, Ismail last_name: Barakat - first_name: Mahmoud full_name: Kalash, Mahmoud last_name: Kalash - first_name: Dennis full_name: Scharwald, Dennis id: '55907' last_name: Scharwald orcid: 0009-0007-5654-5412 - first_name: Polina full_name: Sharapova, Polina id: '60286' last_name: Sharapova - first_name: Norbert full_name: Lindlein, Norbert last_name: Lindlein - first_name: Maria full_name: Chekhova, Maria last_name: Chekhova citation: ama: Barakat I, Kalash M, Scharwald D, Sharapova P, Lindlein N, Chekhova M. Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification. Optica Quantum. 2025;3(1). doi:10.1364/opticaq.524682 apa: Barakat, I., Kalash, M., Scharwald, D., Sharapova, P., Lindlein, N., & Chekhova, M. (2025). Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification. Optica Quantum, 3(1), Article 36. https://doi.org/10.1364/opticaq.524682 bibtex: '@article{Barakat_Kalash_Scharwald_Sharapova_Lindlein_Chekhova_2025, title={Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification}, volume={3}, DOI={10.1364/opticaq.524682}, number={136}, journal={Optica Quantum}, publisher={Optica Publishing Group}, author={Barakat, Ismail and Kalash, Mahmoud and Scharwald, Dennis and Sharapova, Polina and Lindlein, Norbert and Chekhova, Maria}, year={2025} }' chicago: Barakat, Ismail, Mahmoud Kalash, Dennis Scharwald, Polina Sharapova, Norbert Lindlein, and Maria Chekhova. “Simultaneous Measurement of Multimode Squeezing through Multimode Phase-Sensitive Amplification.” Optica Quantum 3, no. 1 (2025). https://doi.org/10.1364/opticaq.524682. ieee: 'I. Barakat, M. Kalash, D. Scharwald, P. Sharapova, N. Lindlein, and M. Chekhova, “Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification,” Optica Quantum, vol. 3, no. 1, Art. no. 36, 2025, doi: 10.1364/opticaq.524682.' mla: Barakat, Ismail, et al. “Simultaneous Measurement of Multimode Squeezing through Multimode Phase-Sensitive Amplification.” Optica Quantum, vol. 3, no. 1, 36, Optica Publishing Group, 2025, doi:10.1364/opticaq.524682. short: I. Barakat, M. Kalash, D. Scharwald, P. Sharapova, N. Lindlein, M. Chekhova, Optica Quantum 3 (2025). date_created: 2026-01-26T15:57:13Z date_updated: 2026-02-10T22:44:44Z department: - _id: '15' - _id: '569' - _id: '170' - _id: '35' - _id: '429' doi: 10.1364/opticaq.524682 intvolume: ' 3' issue: '1' language: - iso: eng main_file_link: - open_access: '1' url: https://opg.optica.org/opticaq/viewmedia.cfm?uri=opticaq-3-1-36&seq=0 oa: '1' project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '56' name: TRR 142 - Project Area C - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Optica Quantum publication_identifier: issn: - 2837-6714 publication_status: published publisher: Optica Publishing Group status: public title: Simultaneous measurement of multimode squeezing through multimode phase-sensitive amplification type: journal_article user_id: '55907' volume: 3 year: '2025' ... --- _id: '58606' author: - first_name: Albert full_name: Mathew, Albert last_name: Mathew - first_name: Rebecca full_name: Aschwanden, Rebecca last_name: Aschwanden - first_name: Aditya full_name: Tripathi, Aditya last_name: Tripathi - first_name: Piyush full_name: Jangid, Piyush last_name: Jangid - first_name: Basudeb full_name: Sain, Basudeb last_name: Sain - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 - first_name: Sergey full_name: Kruk, Sergey last_name: Kruk citation: ama: Mathew A, Aschwanden R, Tripathi A, et al. Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials. Nano Letters. Published online 2025. doi:10.1021/acs.nanolett.4c06188 apa: Mathew, A., Aschwanden, R., Tripathi, A., Jangid, P., Sain, B., Zentgraf, T., & Kruk, S. (2025). Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials. Nano Letters. https://doi.org/10.1021/acs.nanolett.4c06188 bibtex: '@article{Mathew_Aschwanden_Tripathi_Jangid_Sain_Zentgraf_Kruk_2025, title={Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials}, DOI={10.1021/acs.nanolett.4c06188}, journal={Nano Letters}, publisher={American Chemical Society (ACS)}, author={Mathew, Albert and Aschwanden, Rebecca and Tripathi, Aditya and Jangid, Piyush and Sain, Basudeb and Zentgraf, Thomas and Kruk, Sergey}, year={2025} }' chicago: Mathew, Albert, Rebecca Aschwanden, Aditya Tripathi, Piyush Jangid, Basudeb Sain, Thomas Zentgraf, and Sergey Kruk. “Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials.” Nano Letters, 2025. https://doi.org/10.1021/acs.nanolett.4c06188. ieee: 'A. Mathew et al., “Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials,” Nano Letters, 2025, doi: 10.1021/acs.nanolett.4c06188.' mla: Mathew, Albert, et al. “Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials.” Nano Letters, American Chemical Society (ACS), 2025, doi:10.1021/acs.nanolett.4c06188. short: A. Mathew, R. Aschwanden, A. Tripathi, P. Jangid, B. Sain, T. Zentgraf, S. Kruk, Nano Letters (2025). date_created: 2025-02-12T12:54:41Z date_updated: 2025-02-12T13:02:21Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '623' doi: 10.1021/acs.nanolett.4c06188 language: - iso: eng main_file_link: - open_access: '1' url: https://arxiv.org/abs/2501.11920 oa: '1' project: - _id: '53' grant_number: '231447078' name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: 'TRR 142 - A: TRR 142 - Project Area A' - _id: '55' name: 'TRR 142 - B: TRR 142 - Project Area B' - _id: '170' grant_number: '231447078' name: 'TRR 142 - B09: TRR 142 - Effiziente Erzeugung mit maßgeschneiderter optischer Phaselage der zweiten Harmonischen mittels Quasi-gebundener Zustände in GaAs Metaoberflächen (B09*)' - _id: '65' grant_number: '231447078' name: 'TRR 142 - A08: TRR 142 - Nichtlineare Kopplung von Zwischenschicht-Exzitonen in van der Waals-Heterostrukturen an plasmonische und dielektrische Nanokavitäten (A08)' publication: Nano Letters publication_identifier: issn: - 1530-6984 - 1530-6992 publication_status: published publisher: American Chemical Society (ACS) status: public title: Nonreciprocal Metasurfaces with Epsilon-Near-Zero Materials type: journal_article user_id: '30525' year: '2025' ... --- _id: '60565' article_number: '104103' author: - first_name: Adriana full_name: Bocchini, Adriana id: '58349' last_name: Bocchini orcid: 0000-0002-2134-3075 - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 citation: ama: Bocchini A, Gerstmann U, Schmidt WG. Microscopic origin of gray tracks in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>KTiOPO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>. Physical Review B. 2025;111(10). doi:10.1103/physrevb.111.104103 apa: Bocchini, A., Gerstmann, U., & Schmidt, W. G. (2025). Microscopic origin of gray tracks in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>KTiOPO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>. Physical Review B, 111(10), Article 104103. https://doi.org/10.1103/physrevb.111.104103 bibtex: '@article{Bocchini_Gerstmann_Schmidt_2025, title={Microscopic origin of gray tracks in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>KTiOPO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>}, volume={111}, DOI={10.1103/physrevb.111.104103}, number={10104103}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Bocchini, Adriana and Gerstmann, Uwe and Schmidt, Wolf Gero}, year={2025} }' chicago: Bocchini, Adriana, Uwe Gerstmann, and Wolf Gero Schmidt. “Microscopic Origin of Gray Tracks in <mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML"><mml:Msub><mml:Mi>KTiOPO</Mml:Mi><mml:Mn>4</Mml:Mn></Mml:Msub></Mml:Math>.” Physical Review B 111, no. 10 (2025). https://doi.org/10.1103/physrevb.111.104103. ieee: 'A. Bocchini, U. Gerstmann, and W. G. Schmidt, “Microscopic origin of gray tracks in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>KTiOPO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>,” Physical Review B, vol. 111, no. 10, Art. no. 104103, 2025, doi: 10.1103/physrevb.111.104103.' mla: Bocchini, Adriana, et al. “Microscopic Origin of Gray Tracks in <mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML"><mml:Msub><mml:Mi>KTiOPO</Mml:Mi><mml:Mn>4</Mml:Mn></Mml:Msub></Mml:Math>.” Physical Review B, vol. 111, no. 10, 104103, American Physical Society (APS), 2025, doi:10.1103/physrevb.111.104103. short: A. Bocchini, U. Gerstmann, W.G. Schmidt, Physical Review B 111 (2025). date_created: 2025-07-09T08:58:32Z date_updated: 2025-07-09T09:30:31Z department: - _id: '15' - _id: '295' - _id: '790' - _id: '230' - _id: '429' - _id: '35' - _id: '170' - _id: '27' doi: 10.1103/physrevb.111.104103 intvolume: ' 111' issue: '10' language: - iso: eng project: - _id: '52' name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing' - _id: '53' grant_number: '231447078' name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: 'TRR 142 - A: TRR 142 - Project Area A' - _id: '55' name: 'TRR 142 - B: TRR 142 - Project Area B' - _id: '168' grant_number: '231447078' name: 'TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*)' - _id: '166' name: 'TRR 142 - A11: TRR 142 - Subproject A11' publication: Physical Review B publication_identifier: issn: - 2469-9950 - 2469-9969 publication_status: published publisher: American Physical Society (APS) status: public title: Microscopic origin of gray tracks in KTiOPO4 type: journal_article user_id: '16199' volume: 111 year: '2025' ... --- _id: '58642' abstract: - lang: eng text: We present a cost-effective self-assembly method to fabricate low-density dimer NPs in an NPoM architecture, using the M13 phage as a spacer layer. This will enable the development of dynamic plasmonic devices and advanced sensing applications. article_type: original author: - first_name: Vasanthan full_name: Devaraj, Vasanthan id: '103814' last_name: Devaraj - first_name: Isaac Azahel full_name: Ruiz Alvarado, Isaac Azahel id: '79462' last_name: Ruiz Alvarado orcid: 0000-0002-4710-1170 - first_name: Jong-Min full_name: Lee, Jong-Min last_name: Lee - first_name: Jin-Woo full_name: Oh, Jin-Woo last_name: Oh - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 citation: ama: Devaraj V, Ruiz Alvarado IA, Lee J-M, et al. Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror. Nanoscale Horizons. 2025;10:537-548. doi:10.1039/d4nh00546e apa: Devaraj, V., Ruiz Alvarado, I. A., Lee, J.-M., Oh, J.-W., Gerstmann, U., Schmidt, W. G., & Zentgraf, T. (2025). Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror. Nanoscale Horizons, 10, 537–548. https://doi.org/10.1039/d4nh00546e bibtex: '@article{Devaraj_Ruiz Alvarado_Lee_Oh_Gerstmann_Schmidt_Zentgraf_2025, title={Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror}, volume={10}, DOI={10.1039/d4nh00546e}, journal={Nanoscale Horizons}, publisher={Royal Society of Chemistry (RSC)}, author={Devaraj, Vasanthan and Ruiz Alvarado, Isaac Azahel and Lee, Jong-Min and Oh, Jin-Woo and Gerstmann, Uwe and Schmidt, Wolf Gero and Zentgraf, Thomas}, year={2025}, pages={537–548} }' chicago: 'Devaraj, Vasanthan, Isaac Azahel Ruiz Alvarado, Jong-Min Lee, Jin-Woo Oh, Uwe Gerstmann, Wolf Gero Schmidt, and Thomas Zentgraf. “Self-Assembly of Isolated Plasmonic Dimers with Sub-5 Nm Gaps on a Metallic Mirror.” Nanoscale Horizons 10 (2025): 537–48. https://doi.org/10.1039/d4nh00546e.' ieee: 'V. Devaraj et al., “Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror,” Nanoscale Horizons, vol. 10, pp. 537–548, 2025, doi: 10.1039/d4nh00546e.' mla: Devaraj, Vasanthan, et al. “Self-Assembly of Isolated Plasmonic Dimers with Sub-5 Nm Gaps on a Metallic Mirror.” Nanoscale Horizons, vol. 10, Royal Society of Chemistry (RSC), 2025, pp. 537–48, doi:10.1039/d4nh00546e. short: V. Devaraj, I.A. Ruiz Alvarado, J.-M. Lee, J.-W. Oh, U. Gerstmann, W.G. Schmidt, T. Zentgraf, Nanoscale Horizons 10 (2025) 537–548. date_created: 2025-02-14T08:13:10Z date_updated: 2025-07-09T14:04:39Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '623' - _id: '35' - _id: '295' - _id: '170' - _id: '429' - _id: '27' doi: 10.1039/d4nh00546e intvolume: ' 10' language: - iso: eng page: 537-548 project: - _id: '53' grant_number: '231447078' name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '168' grant_number: '231447078' name: 'TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*)' - _id: '55' name: 'TRR 142 - B: TRR 142 - Project Area B' - _id: '445' grant_number: '367360193' name: Hochleistungsrechner Noctua in Paderborn - _id: '52' name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing' publication: Nanoscale Horizons publication_identifier: issn: - 2055-6756 - 2055-6764 publication_status: published publisher: Royal Society of Chemistry (RSC) quality_controlled: '1' status: public title: Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror type: journal_article user_id: '16199' volume: 10 year: '2025' ... --- _id: '61245' article_number: '032404' author: - first_name: Franziska full_name: Barkhausen, Franziska id: '63631' last_name: Barkhausen - first_name: Laura full_name: Ares Santos, Laura last_name: Ares Santos - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 - first_name: Jan full_name: Sperling, Jan id: '75127' last_name: Sperling orcid: 0000-0002-5844-3205 citation: ama: 'Barkhausen F, Ares Santos L, Schumacher S, Sperling J. Entanglement between dependent degrees of freedom: Quasiparticle correlations. Physical Review A. 2025;111(3). doi:10.1103/physreva.111.032404' apa: 'Barkhausen, F., Ares Santos, L., Schumacher, S., & Sperling, J. (2025). Entanglement between dependent degrees of freedom: Quasiparticle correlations. Physical Review A, 111(3), Article 032404. https://doi.org/10.1103/physreva.111.032404' bibtex: '@article{Barkhausen_Ares Santos_Schumacher_Sperling_2025, title={Entanglement between dependent degrees of freedom: Quasiparticle correlations}, volume={111}, DOI={10.1103/physreva.111.032404}, number={3032404}, journal={Physical Review A}, publisher={American Physical Society (APS)}, author={Barkhausen, Franziska and Ares Santos, Laura and Schumacher, Stefan and Sperling, Jan}, year={2025} }' chicago: 'Barkhausen, Franziska, Laura Ares Santos, Stefan Schumacher, and Jan Sperling. “Entanglement between Dependent Degrees of Freedom: Quasiparticle Correlations.” Physical Review A 111, no. 3 (2025). https://doi.org/10.1103/physreva.111.032404.' ieee: 'F. Barkhausen, L. Ares Santos, S. Schumacher, and J. Sperling, “Entanglement between dependent degrees of freedom: Quasiparticle correlations,” Physical Review A, vol. 111, no. 3, Art. no. 032404, 2025, doi: 10.1103/physreva.111.032404.' mla: 'Barkhausen, Franziska, et al. “Entanglement between Dependent Degrees of Freedom: Quasiparticle Correlations.” Physical Review A, vol. 111, no. 3, 032404, American Physical Society (APS), 2025, doi:10.1103/physreva.111.032404.' short: F. Barkhausen, L. Ares Santos, S. Schumacher, J. Sperling, Physical Review A 111 (2025). date_created: 2025-09-12T10:37:34Z date_updated: 2025-09-12T10:42:16Z department: - _id: '15' - _id: '170' - _id: '297' - _id: '706' - _id: '35' - _id: '230' - _id: '623' - _id: '429' doi: 10.1103/physreva.111.032404 intvolume: ' 111' issue: '3' language: - iso: eng project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: TRR 142 - Project Area A - _id: '56' name: TRR 142 - Project Area C - _id: '61' name: 'TRR 142; TP A04: Nichtlineare Quantenprozesstomographie und Photonik mit Polaritonen in Mikrokavitäten' - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' - _id: '266' name: 'PhoQC: Photonisches Quantencomputing' publication: Physical Review A publication_identifier: issn: - 2469-9926 - 2469-9934 publication_status: published publisher: American Physical Society (APS) status: public title: 'Entanglement between dependent degrees of freedom: Quasiparticle correlations' type: journal_article user_id: '16199' volume: 111 year: '2025' ... --- _id: '61351' abstract: - lang: eng text: AbstractThe interaction of water molecules with semiconductor surfaces is relevant to various optoelectronic phenomena and physicochemical processes. Despite advances in fundamental understanding of water‐exposed surfaces, the detailed time‐ and energy‐resolved behavior of excited electrons remains largely unexplored. Here, the effects of water exposure on the near‐surface electron dynamics of phosphorus‐terminated p(2×2)/c(4×2)‐reconstructed indium phosphide (100) (P‐rich InP) are studied experimentally and matched to theoretical calculations. The P‐rich InP surface, consisting of H‐passivated P‐dimers, serves as a model for other P‐containing III‐V semiconductors such as gallium phosphide (GaP) or aluminum indium phosphide (AlInP). Electron dynamics near the surface are probed with femtosecond resolution using time‐resolved two‐photon photoemission (tr‐2PPE), a pump‐probe spectroscopic technique. Pulsed water exposure preserves electronic states and significantly increases lifetimes at the conduction band minimum (CBM). Density‐functional theory (DFT) calculations attribute these findings to suppression of surface vibrational modes in the top P‐layer by water exposure, reducing electronic transition probabilities of near‐band‐gap surface states. The results suggest that many near‐surface state lifetimes reported in ultra‐high vacuum may change significantly upon electrolyte exposure. These states may thus contribute more strongly to surface reactions than traditionally assumed. Demonstrating this effect for the technologically relevant P‐rich InP surface opens new opportunities in this underexplored area of surface electrochemistry. article_number: e00463 author: - first_name: Jonathan full_name: Diederich, Jonathan last_name: Diederich - first_name: Agnieszka full_name: Paszuk, Agnieszka last_name: Paszuk - first_name: Isaac Azahel full_name: Ruiz Alvarado, Isaac Azahel id: '79462' last_name: Ruiz Alvarado orcid: 0000-0002-4710-1170 - first_name: Marvin full_name: Krenz, Marvin last_name: Krenz - first_name: Mohammad Amin full_name: Zare Pour, Mohammad Amin last_name: Zare Pour - first_name: Diwakar Suresh full_name: Babu, Diwakar Suresh last_name: Babu - first_name: Jennifer full_name: Velazquez Rojas, Jennifer last_name: Velazquez Rojas - first_name: Christian full_name: Höhn, Christian last_name: Höhn - first_name: Yuying full_name: Gao, Yuying last_name: Gao - first_name: Klaus full_name: Schwarzburg, Klaus last_name: Schwarzburg - first_name: David full_name: Ostheimer, David last_name: Ostheimer - first_name: Rainer full_name: Eichberger, Rainer last_name: Eichberger - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Thomas full_name: Hannappel, Thomas last_name: Hannappel - first_name: Roel van full_name: de Krol, Roel van last_name: de Krol - first_name: Dennis full_name: Friedrich, Dennis last_name: Friedrich citation: ama: Diederich J, Paszuk A, Ruiz Alvarado IA, et al. Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface. Advanced Materials Interfaces. 2025;12(16). doi:10.1002/admi.202500463 apa: Diederich, J., Paszuk, A., Ruiz Alvarado, I. A., Krenz, M., Zare Pour, M. A., Babu, D. S., Velazquez Rojas, J., Höhn, C., Gao, Y., Schwarzburg, K., Ostheimer, D., Eichberger, R., Schmidt, W. G., Hannappel, T., de Krol, R. van, & Friedrich, D. (2025). Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface. Advanced Materials Interfaces, 12(16), Article e00463. https://doi.org/10.1002/admi.202500463 bibtex: '@article{Diederich_Paszuk_Ruiz Alvarado_Krenz_Zare Pour_Babu_Velazquez Rojas_Höhn_Gao_Schwarzburg_et al._2025, title={Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface}, volume={12}, DOI={10.1002/admi.202500463}, number={16e00463}, journal={Advanced Materials Interfaces}, publisher={Wiley}, author={Diederich, Jonathan and Paszuk, Agnieszka and Ruiz Alvarado, Isaac Azahel and Krenz, Marvin and Zare Pour, Mohammad Amin and Babu, Diwakar Suresh and Velazquez Rojas, Jennifer and Höhn, Christian and Gao, Yuying and Schwarzburg, Klaus and et al.}, year={2025} }' chicago: Diederich, Jonathan, Agnieszka Paszuk, Isaac Azahel Ruiz Alvarado, Marvin Krenz, Mohammad Amin Zare Pour, Diwakar Suresh Babu, Jennifer Velazquez Rojas, et al. “Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface.” Advanced Materials Interfaces 12, no. 16 (2025). https://doi.org/10.1002/admi.202500463. ieee: 'J. Diederich et al., “Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface,” Advanced Materials Interfaces, vol. 12, no. 16, Art. no. e00463, 2025, doi: 10.1002/admi.202500463.' mla: Diederich, Jonathan, et al. “Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface.” Advanced Materials Interfaces, vol. 12, no. 16, e00463, Wiley, 2025, doi:10.1002/admi.202500463. short: J. Diederich, A. Paszuk, I.A. Ruiz Alvarado, M. Krenz, M.A. Zare Pour, D.S. Babu, J. Velazquez Rojas, C. Höhn, Y. Gao, K. Schwarzburg, D. Ostheimer, R. Eichberger, W.G. Schmidt, T. Hannappel, R. van de Krol, D. Friedrich, Advanced Materials Interfaces 12 (2025). date_created: 2025-09-18T11:03:16Z date_updated: 2025-09-18T11:06:59Z department: - _id: '15' - _id: '170' - _id: '295' - _id: '35' - _id: '230' - _id: '27' - _id: '429' doi: 10.1002/admi.202500463 intvolume: ' 12' issue: '16' language: - iso: eng project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '55' name: TRR 142 - Project Area B - _id: '168' name: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*) - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Advanced Materials Interfaces publication_identifier: issn: - 2196-7350 - 2196-7350 publication_status: published publisher: Wiley status: public title: Ultrafast Electron Dynamics at the Water‐Modified InP(100) Surface type: journal_article user_id: '16199' volume: 12 year: '2025' ... --- _id: '61356' abstract: - lang: eng text: First-principles calculations reveal how topological defects in semiconducting carbon nanotubes trap triplet excitons and enable single-photon emission at telecom wavelengths, offering new insights into their potential for photonic devices. author: - first_name: Timur full_name: Biktagirov, Timur id: '65612' last_name: Biktagirov - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 citation: ama: Biktagirov T, Gerstmann U, Schmidt WG. Topological defects in semiconducting carbon nanotubes as triplet exciton traps and single-photon emitters. Nanoscale. 2025;17(11):6884-6891. doi:10.1039/d4nr03904a apa: Biktagirov, T., Gerstmann, U., & Schmidt, W. G. (2025). Topological defects in semiconducting carbon nanotubes as triplet exciton traps and single-photon emitters. Nanoscale, 17(11), 6884–6891. https://doi.org/10.1039/d4nr03904a bibtex: '@article{Biktagirov_Gerstmann_Schmidt_2025, title={Topological defects in semiconducting carbon nanotubes as triplet exciton traps and single-photon emitters}, volume={17}, DOI={10.1039/d4nr03904a}, number={11}, journal={Nanoscale}, publisher={Royal Society of Chemistry (RSC)}, author={Biktagirov, Timur and Gerstmann, Uwe and Schmidt, Wolf Gero}, year={2025}, pages={6884–6891} }' chicago: 'Biktagirov, Timur, Uwe Gerstmann, and Wolf Gero Schmidt. “Topological Defects in Semiconducting Carbon Nanotubes as Triplet Exciton Traps and Single-Photon Emitters.” Nanoscale 17, no. 11 (2025): 6884–91. https://doi.org/10.1039/d4nr03904a.' ieee: 'T. Biktagirov, U. Gerstmann, and W. G. Schmidt, “Topological defects in semiconducting carbon nanotubes as triplet exciton traps and single-photon emitters,” Nanoscale, vol. 17, no. 11, pp. 6884–6891, 2025, doi: 10.1039/d4nr03904a.' mla: Biktagirov, Timur, et al. “Topological Defects in Semiconducting Carbon Nanotubes as Triplet Exciton Traps and Single-Photon Emitters.” Nanoscale, vol. 17, no. 11, Royal Society of Chemistry (RSC), 2025, pp. 6884–91, doi:10.1039/d4nr03904a. short: T. Biktagirov, U. Gerstmann, W.G. Schmidt, Nanoscale 17 (2025) 6884–6891. date_created: 2025-09-18T11:23:25Z date_updated: 2025-09-18T11:26:23Z department: - _id: '15' - _id: '170' - _id: '295' - _id: '790' - _id: '35' - _id: '230' - _id: '27' - _id: '429' doi: 10.1039/d4nr03904a intvolume: ' 17' issue: '11' language: - iso: eng page: 6884-6891 project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: TRR 142 - Project Area A - _id: '55' name: TRR 142 - Project Area B - _id: '168' name: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*) - _id: '166' name: TRR 142 - Subproject A11 publication: Nanoscale publication_identifier: issn: - 2040-3364 - 2040-3372 publication_status: published publisher: Royal Society of Chemistry (RSC) status: public title: Topological defects in semiconducting carbon nanotubes as triplet exciton traps and single-photon emitters type: journal_article user_id: '16199' volume: 17 year: '2025' ... --- _id: '60891' abstract: - lang: eng text: Straight dielectric waveguide channels made from slabs of thin-film lithium niobate (TFLN), or lithium niobate on insulator (LNOI), are investigated in the linear regime, for channels of rib and strip type with common trapezoidal cross sections, in Z-cut and X-cut samples at varying on-chip orientation. We clarify the theoretical basis for the waveguides with potentially non-diagonal core permittivity. Symmetry classes can be distinguished that differ in their consequences for potential modal degeneracy and polarization conversion. Our rigorous numerical analysis by means of a finite-element solver takes the anisotropy of the lithium niobate cores rigorously into account. We discuss extensive data for effective indices, polarization properties, and hybridization of guided modes, in single- and multimode channels. Scans over the waveguide width and orientation as primary parameters are complemented by a series of illustrations of vectorial mode profiles. These turn out to be essentially complex in cases of X-cut channels at non-crystal-axis-aligned orientations. author: - first_name: Manfred full_name: Hammer, Manfred id: '48077' last_name: Hammer orcid: 0000-0002-6331-9348 - first_name: Shahriar full_name: Khan, Shahriar last_name: Khan - first_name: Behnood full_name: Taheri, Behnood last_name: Taheri - first_name: Henna full_name: Farheen, Henna id: '53444' last_name: Farheen orcid: 0000-0001-7730-3489 - first_name: Jens full_name: Förstner, Jens id: '158' last_name: Förstner orcid: 0000-0001-7059-9862 citation: ama: 'Hammer M, Khan S, Taheri B, Farheen H, Förstner J. TFLN channel waveguides of rib and strip type: Properties of guided modes. Optics Continuum. 2025;4(10):2356. doi:10.1364/optcon.569959' apa: 'Hammer, M., Khan, S., Taheri, B., Farheen, H., & Förstner, J. (2025). TFLN channel waveguides of rib and strip type: Properties of guided modes. Optics Continuum, 4(10), 2356. https://doi.org/10.1364/optcon.569959' bibtex: '@article{Hammer_Khan_Taheri_Farheen_Förstner_2025, title={TFLN channel waveguides of rib and strip type: Properties of guided modes}, volume={4}, DOI={10.1364/optcon.569959}, number={10}, journal={Optics Continuum}, publisher={Optica Publishing Group}, author={Hammer, Manfred and Khan, Shahriar and Taheri, Behnood and Farheen, Henna and Förstner, Jens}, year={2025}, pages={2356} }' chicago: 'Hammer, Manfred, Shahriar Khan, Behnood Taheri, Henna Farheen, and Jens Förstner. “TFLN Channel Waveguides of Rib and Strip Type: Properties of Guided Modes.” Optics Continuum 4, no. 10 (2025): 2356. https://doi.org/10.1364/optcon.569959.' ieee: 'M. Hammer, S. Khan, B. Taheri, H. Farheen, and J. Förstner, “TFLN channel waveguides of rib and strip type: Properties of guided modes,” Optics Continuum, vol. 4, no. 10, p. 2356, 2025, doi: 10.1364/optcon.569959.' mla: 'Hammer, Manfred, et al. “TFLN Channel Waveguides of Rib and Strip Type: Properties of Guided Modes.” Optics Continuum, vol. 4, no. 10, Optica Publishing Group, 2025, p. 2356, doi:10.1364/optcon.569959.' short: M. Hammer, S. Khan, B. Taheri, H. Farheen, J. Förstner, Optics Continuum 4 (2025) 2356. date_created: 2025-08-06T09:36:30Z date_updated: 2025-10-05T11:52:55Z ddc: - '530' department: - _id: '61' - _id: '230' - _id: '429' - _id: '623' doi: 10.1364/optcon.569959 file: - access_level: closed content_type: application/pdf creator: fossie date_created: 2025-10-05T11:48:25Z date_updated: 2025-10-05T11:48:25Z file_id: '61516' file_name: 2025-08 Hammer - Optics Continuum - TFLN channel waveguides of rib and strip type. Properties of guided modes (official version).pdf file_size: 5417636 relation: main_file success: 1 file_date_updated: 2025-10-05T11:48:25Z has_accepted_license: '1' intvolume: ' 4' issue: '10' keyword: - tet_topic_waveguide language: - iso: eng page: '2356' publication: Optics Continuum publication_identifier: issn: - 2770-0208 publication_status: published publisher: Optica Publishing Group status: public title: 'TFLN channel waveguides of rib and strip type: Properties of guided modes' type: journal_article user_id: '158' volume: 4 year: '2025' ... --- _id: '61760' abstract: - lang: eng text: We present a topology-optimized silicon nitride (Si3N4) coupler designed to enhance the coupling efficiency between integrated single-photon emitters and photonic waveguide modes. By leveraging inverse design techniques, we optimize the coupler’s geometry to maximize power transfer while maintaining fabrication feasibility by improving mode overlap and directional emission, addressing the challenge of low coupling efficiency caused by size mismatch and material incompatibility. Simulations demonstrate a substantial enhancement in photon extraction and waveguide coupling. This approach can be extended to other photonic devices, offering a versatile framework for improving quantum light-matter interactions in integrated photonics. author: - first_name: Henna full_name: Farheen, Henna id: '53444' last_name: Farheen orcid: 0000-0001-7730-3489 - first_name: Yuheng full_name: Chen, Yuheng last_name: Chen - first_name: Peigang full_name: Chen, Peigang last_name: Chen - first_name: Artem full_name: Kryvobok, Artem last_name: Kryvobok - first_name: Samuel full_name: Peana, Samuel last_name: Peana - first_name: Alexander full_name: Senichev, Alexander last_name: Senichev - first_name: Vladimir M. full_name: Shalaev, Vladimir M. last_name: Shalaev - first_name: Alexandra full_name: Boltasseva, Alexandra last_name: Boltasseva - first_name: Jens full_name: Förstner, Jens id: '158' last_name: Förstner orcid: 0000-0001-7059-9862 - first_name: Alexander V. full_name: Kildishev, Alexander V. last_name: Kildishev citation: ama: 'Farheen H, Chen Y, Chen P, et al. Topology-optimized silicon nitride coupler for integrated single-photon emitters. In: Ni X, Cai W, eds. Photonic Computing: From Materials and Devices to Systems and Applications II. SPIE; 2025. doi:10.1117/12.3065734' apa: 'Farheen, H., Chen, Y., Chen, P., Kryvobok, A., Peana, S., Senichev, A., Shalaev, V. M., Boltasseva, A., Förstner, J., & Kildishev, A. V. (2025). Topology-optimized silicon nitride coupler for integrated single-photon emitters. In X. Ni & W. Cai (Eds.), Photonic Computing: From Materials and Devices to Systems and Applications II. SPIE. https://doi.org/10.1117/12.3065734' bibtex: '@inproceedings{Farheen_Chen_Chen_Kryvobok_Peana_Senichev_Shalaev_Boltasseva_Förstner_Kildishev_2025, title={Topology-optimized silicon nitride coupler for integrated single-photon emitters}, DOI={10.1117/12.3065734}, booktitle={Photonic Computing: From Materials and Devices to Systems and Applications II}, publisher={SPIE}, author={Farheen, Henna and Chen, Yuheng and Chen, Peigang and Kryvobok, Artem and Peana, Samuel and Senichev, Alexander and Shalaev, Vladimir M. and Boltasseva, Alexandra and Förstner, Jens and Kildishev, Alexander V.}, editor={Ni, Xingjie and Cai, Wenshan}, year={2025} }' chicago: 'Farheen, Henna, Yuheng Chen, Peigang Chen, Artem Kryvobok, Samuel Peana, Alexander Senichev, Vladimir M. Shalaev, Alexandra Boltasseva, Jens Förstner, and Alexander V. Kildishev. “Topology-Optimized Silicon Nitride Coupler for Integrated Single-Photon Emitters.” In Photonic Computing: From Materials and Devices to Systems and Applications II, edited by Xingjie Ni and Wenshan Cai. SPIE, 2025. https://doi.org/10.1117/12.3065734.' ieee: 'H. Farheen et al., “Topology-optimized silicon nitride coupler for integrated single-photon emitters,” in Photonic Computing: From Materials and Devices to Systems and Applications II, 2025, doi: 10.1117/12.3065734.' mla: 'Farheen, Henna, et al. “Topology-Optimized Silicon Nitride Coupler for Integrated Single-Photon Emitters.” Photonic Computing: From Materials and Devices to Systems and Applications II, edited by Xingjie Ni and Wenshan Cai, SPIE, 2025, doi:10.1117/12.3065734.' short: 'H. Farheen, Y. Chen, P. Chen, A. Kryvobok, S. Peana, A. Senichev, V.M. Shalaev, A. Boltasseva, J. Förstner, A.V. Kildishev, in: X. Ni, W. Cai (Eds.), Photonic Computing: From Materials and Devices to Systems and Applications II, SPIE, 2025.' date_created: 2025-10-08T15:20:13Z date_updated: 2025-10-08T15:22:30Z department: - _id: '61' - _id: '230' - _id: '429' - _id: '623' doi: 10.1117/12.3065734 editor: - first_name: Xingjie full_name: Ni, Xingjie last_name: Ni - first_name: Wenshan full_name: Cai, Wenshan last_name: Cai keyword: - tet_topic_waveguide language: - iso: eng publication: 'Photonic Computing: From Materials and Devices to Systems and Applications II' publication_status: published publisher: SPIE status: public title: Topology-optimized silicon nitride coupler for integrated single-photon emitters type: conference user_id: '158' year: '2025' ... --- _id: '62057' abstract: - lang: eng text: "Abstract\r\n Time-resolved momentum microscopy is an emerging technique based on photoelectron spectroscopy for characterizing ultrafast electron dynamics and the out-of-equilibrium electronic structure of materials in the entire Brillouin zone with high efficiency. In this article, we introduce a setup for time-resolved momentum microscopy based on an energy-filtered momentum microscope coupled to a custom-made high-harmonic generation photon source driven by a multi-100 kHz commercial Yb-ultrafast laser that delivers fs pulses in the extreme ultraviolet range. The laser setup includes a nonlinear pulse compression stage employing spectral broadening in a Herriott-type bulk-based multi-pass cell. This element allows flexible tuning of the driving pulse duration, providing a versatile time-resolved momentum microscopy setup featuring two operational modes designed to enhance either the energy or time resolution. We show the capabilities of the system by tracing ultrafast electron dynamics in the conduction band valleys of a bulk crystal of the 2D semiconductor WS2. Using uncompressed driving laser pulses, we demonstrate an energy resolution better than (107 ± 2) meV, while compressed pulses lead to a time resolution better than (48.8 ± 17) fs." article_number: '3611' author: - first_name: Karl Jakob full_name: Schiller, Karl Jakob last_name: Schiller - first_name: Lasse full_name: Sternemann, Lasse last_name: Sternemann - first_name: Matija full_name: Stupar, Matija last_name: Stupar - first_name: Alan full_name: Omar, Alan last_name: Omar - first_name: Martin full_name: Hoffmann, Martin last_name: Hoffmann - first_name: Jonah Elias full_name: Nitschke, Jonah Elias last_name: Nitschke - first_name: Valentin full_name: Mischke, Valentin last_name: Mischke - first_name: David Maximilian full_name: Janas, David Maximilian last_name: Janas - first_name: Stefano full_name: Ponzoni, Stefano last_name: Ponzoni - first_name: Giovanni full_name: Zamborlini, Giovanni last_name: Zamborlini - first_name: Clara Jody full_name: Saraceno, Clara Jody last_name: Saraceno - first_name: Mirko full_name: Cinchetti, Mirko last_name: Cinchetti citation: ama: Schiller KJ, Sternemann L, Stupar M, et al. Time-resolved momentum microscopy with fs-XUV photons at high repetition rates with flexible energy and time resolution. Scientific Reports. 2025;15(1). doi:10.1038/s41598-025-86660-1 apa: Schiller, K. J., Sternemann, L., Stupar, M., Omar, A., Hoffmann, M., Nitschke, J. E., Mischke, V., Janas, D. M., Ponzoni, S., Zamborlini, G., Saraceno, C. J., & Cinchetti, M. (2025). Time-resolved momentum microscopy with fs-XUV photons at high repetition rates with flexible energy and time resolution. Scientific Reports, 15(1), Article 3611. https://doi.org/10.1038/s41598-025-86660-1 bibtex: '@article{Schiller_Sternemann_Stupar_Omar_Hoffmann_Nitschke_Mischke_Janas_Ponzoni_Zamborlini_et al._2025, title={Time-resolved momentum microscopy with fs-XUV photons at high repetition rates with flexible energy and time resolution}, volume={15}, DOI={10.1038/s41598-025-86660-1}, number={13611}, journal={Scientific Reports}, publisher={Springer Science and Business Media LLC}, author={Schiller, Karl Jakob and Sternemann, Lasse and Stupar, Matija and Omar, Alan and Hoffmann, Martin and Nitschke, Jonah Elias and Mischke, Valentin and Janas, David Maximilian and Ponzoni, Stefano and Zamborlini, Giovanni and et al.}, year={2025} }' chicago: Schiller, Karl Jakob, Lasse Sternemann, Matija Stupar, Alan Omar, Martin Hoffmann, Jonah Elias Nitschke, Valentin Mischke, et al. “Time-Resolved Momentum Microscopy with Fs-XUV Photons at High Repetition Rates with Flexible Energy and Time Resolution.” Scientific Reports 15, no. 1 (2025). https://doi.org/10.1038/s41598-025-86660-1. ieee: 'K. J. Schiller et al., “Time-resolved momentum microscopy with fs-XUV photons at high repetition rates with flexible energy and time resolution,” Scientific Reports, vol. 15, no. 1, Art. no. 3611, 2025, doi: 10.1038/s41598-025-86660-1.' mla: Schiller, Karl Jakob, et al. “Time-Resolved Momentum Microscopy with Fs-XUV Photons at High Repetition Rates with Flexible Energy and Time Resolution.” Scientific Reports, vol. 15, no. 1, 3611, Springer Science and Business Media LLC, 2025, doi:10.1038/s41598-025-86660-1. short: K.J. Schiller, L. Sternemann, M. Stupar, A. Omar, M. Hoffmann, J.E. Nitschke, V. Mischke, D.M. Janas, S. Ponzoni, G. Zamborlini, C.J. Saraceno, M. Cinchetti, Scientific Reports 15 (2025). date_created: 2025-11-04T07:47:28Z date_updated: 2025-11-04T07:48:50Z doi: 10.1038/s41598-025-86660-1 intvolume: ' 15' issue: '1' language: - iso: eng project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: TRR 142 - Project Area A - _id: '65' name: 'TRR 142; TP A08: Nichtlineare Kopplung von Zwischenschicht-Exzitonen in van der Waals-Heterostrukturen an plasmonische und dielektrische Nanokavitäten' publication: Scientific Reports publication_identifier: issn: - 2045-2322 publication_status: published publisher: Springer Science and Business Media LLC status: public title: Time-resolved momentum microscopy with fs-XUV photons at high repetition rates with flexible energy and time resolution type: journal_article user_id: '30525' volume: 15 year: '2025' ... --- _id: '62059' article_number: '100019' author: - first_name: Jonah Elias full_name: Nitschke, Jonah Elias last_name: Nitschke - first_name: Lasse full_name: Sternemann, Lasse last_name: Sternemann - first_name: Michael full_name: Gutnikov, Michael last_name: Gutnikov - first_name: Karl full_name: Schiller, Karl last_name: Schiller - first_name: Eugenio full_name: Coronado, Eugenio last_name: Coronado - first_name: Alan full_name: Omar, Alan last_name: Omar - first_name: Giovanni full_name: Zamborlini, Giovanni last_name: Zamborlini - first_name: Clara full_name: Saraceno, Clara last_name: Saraceno - first_name: Matija full_name: Stupar, Matija last_name: Stupar - first_name: Alberto M. full_name: Ruiz, Alberto M. last_name: Ruiz - first_name: Dorye L. full_name: Esteras, Dorye L. last_name: Esteras - first_name: José J. full_name: Baldoví, José J. last_name: Baldoví - first_name: Frithjof full_name: Anders, Frithjof last_name: Anders - first_name: Mirko full_name: Cinchetti, Mirko last_name: Cinchetti citation: ama: Nitschke JE, Sternemann L, Gutnikov M, et al. Tracing the ultrafast buildup and decay of d-d transitions in FePS3. Newton. 2025;1(2). doi:10.1016/j.newton.2025.100019 apa: Nitschke, J. E., Sternemann, L., Gutnikov, M., Schiller, K., Coronado, E., Omar, A., Zamborlini, G., Saraceno, C., Stupar, M., Ruiz, A. M., Esteras, D. L., Baldoví, J. J., Anders, F., & Cinchetti, M. (2025). Tracing the ultrafast buildup and decay of d-d transitions in FePS3. Newton, 1(2), Article 100019. https://doi.org/10.1016/j.newton.2025.100019 bibtex: '@article{Nitschke_Sternemann_Gutnikov_Schiller_Coronado_Omar_Zamborlini_Saraceno_Stupar_Ruiz_et al._2025, title={Tracing the ultrafast buildup and decay of d-d transitions in FePS3}, volume={1}, DOI={10.1016/j.newton.2025.100019}, number={2100019}, journal={Newton}, publisher={Elsevier BV}, author={Nitschke, Jonah Elias and Sternemann, Lasse and Gutnikov, Michael and Schiller, Karl and Coronado, Eugenio and Omar, Alan and Zamborlini, Giovanni and Saraceno, Clara and Stupar, Matija and Ruiz, Alberto M. and et al.}, year={2025} }' chicago: Nitschke, Jonah Elias, Lasse Sternemann, Michael Gutnikov, Karl Schiller, Eugenio Coronado, Alan Omar, Giovanni Zamborlini, et al. “Tracing the Ultrafast Buildup and Decay of D-d Transitions in FePS3.” Newton 1, no. 2 (2025). https://doi.org/10.1016/j.newton.2025.100019. ieee: 'J. E. Nitschke et al., “Tracing the ultrafast buildup and decay of d-d transitions in FePS3,” Newton, vol. 1, no. 2, Art. no. 100019, 2025, doi: 10.1016/j.newton.2025.100019.' mla: Nitschke, Jonah Elias, et al. “Tracing the Ultrafast Buildup and Decay of D-d Transitions in FePS3.” Newton, vol. 1, no. 2, 100019, Elsevier BV, 2025, doi:10.1016/j.newton.2025.100019. short: J.E. Nitschke, L. Sternemann, M. Gutnikov, K. Schiller, E. Coronado, A. Omar, G. Zamborlini, C. Saraceno, M. Stupar, A.M. Ruiz, D.L. Esteras, J.J. Baldoví, F. Anders, M. Cinchetti, Newton 1 (2025). date_created: 2025-11-04T07:49:08Z date_updated: 2025-11-04T07:49:39Z doi: 10.1016/j.newton.2025.100019 intvolume: ' 1' issue: '2' language: - iso: eng project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: TRR 142 - Project Area A - _id: '65' name: 'TRR 142; TP A08: Nichtlineare Kopplung von Zwischenschicht-Exzitonen in van der Waals-Heterostrukturen an plasmonische und dielektrische Nanokavitäten' publication: Newton publication_identifier: issn: - 2950-6360 publication_status: published publisher: Elsevier BV status: public title: Tracing the ultrafast buildup and decay of d-d transitions in FePS3 type: journal_article user_id: '30525' volume: 1 year: '2025' ... --- _id: '62911' abstract: - lang: eng text: In this paper, we theoretically study the spectral and temporal properties of pulsed spontaneous parametric down-conversion (SPDC) generated in lossy waveguides. Our theoretical approach is based on the formalism of Gaussian states and the Langevin equation, which is elaborated for weak parametric down-conversion and photon-number-unresolved click detection. Using the example of frequency-degenerate type-II SPDC generated under the pump-idler group-velocity-matching condition, we show how the joint-spectral intensity, mode structure, normalized second-order correlation function, and Hong-Ou-Mandel interference pattern depend on internal losses of the SPDC process. We found that the joint-spectral intensity is almost insensitive to internal losses, while the second-order correlation function shows a strong dependence on them, being different for the signal and idler beams in the presence of internal losses. Based on the sensitivity of the normalized second-order correlation function, we show how its measurement can be used to experimentally determine internal losses. article_number: '033122' author: - first_name: Denis A. full_name: Kopylov, Denis A. last_name: Kopylov - first_name: Michael full_name: Stefszky, Michael id: '42777' last_name: Stefszky - first_name: Torsten full_name: Meier, Torsten id: '344' last_name: Meier orcid: 0000-0001-8864-2072 - first_name: Christine full_name: Silberhorn, Christine id: '26263' last_name: Silberhorn - first_name: Polina R. full_name: Sharapova, Polina R. id: '60286' last_name: Sharapova citation: ama: 'Kopylov DA, Stefszky M, Meier T, Silberhorn C, Sharapova PR. Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation. Physical Review Research. 2025;7(3). doi:10.1103/zp72-7qwl' apa: 'Kopylov, D. A., Stefszky, M., Meier, T., Silberhorn, C., & Sharapova, P. R. (2025). Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation. Physical Review Research, 7(3), Article 033122. https://doi.org/10.1103/zp72-7qwl' bibtex: '@article{Kopylov_Stefszky_Meier_Silberhorn_Sharapova_2025, title={Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation}, volume={7}, DOI={10.1103/zp72-7qwl}, number={3033122}, journal={Physical Review Research}, publisher={American Physical Society (APS)}, author={Kopylov, Denis A. and Stefszky, Michael and Meier, Torsten and Silberhorn, Christine and Sharapova, Polina R.}, year={2025} }' chicago: 'Kopylov, Denis A., Michael Stefszky, Torsten Meier, Christine Silberhorn, and Polina R. Sharapova. “Spectral and Temporal Properties of Type-II Parametric down-Conversion: The Impact of Losses during State Generation.” Physical Review Research 7, no. 3 (2025). https://doi.org/10.1103/zp72-7qwl.' ieee: 'D. A. Kopylov, M. Stefszky, T. Meier, C. Silberhorn, and P. R. Sharapova, “Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation,” Physical Review Research, vol. 7, no. 3, Art. no. 033122, 2025, doi: 10.1103/zp72-7qwl.' mla: 'Kopylov, Denis A., et al. “Spectral and Temporal Properties of Type-II Parametric down-Conversion: The Impact of Losses during State Generation.” Physical Review Research, vol. 7, no. 3, 033122, American Physical Society (APS), 2025, doi:10.1103/zp72-7qwl.' short: D.A. Kopylov, M. Stefszky, T. Meier, C. Silberhorn, P.R. Sharapova, Physical Review Research 7 (2025). date_created: 2025-12-05T09:33:36Z date_updated: 2025-12-05T09:55:22Z department: - _id: '15' - _id: '569' - _id: '170' - _id: '293' - _id: '288' - _id: '230' - _id: '623' - _id: '429' - _id: '35' doi: 10.1103/zp72-7qwl intvolume: ' 7' issue: '3' language: - iso: eng project: - _id: '266' name: 'PhoQC: Photonisches Quantencomputing' - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '56' name: TRR 142 - Project Area C - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' publication: Physical Review Research publication_identifier: issn: - 2643-1564 publication_status: published publisher: American Physical Society (APS) status: public title: 'Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation' type: journal_article user_id: '16199' volume: 7 year: '2025' ... --- _id: '60568' article_number: '122776' author: - first_name: Adriana full_name: Bocchini, Adriana id: '58349' last_name: Bocchini orcid: 0000-0002-2134-3075 - first_name: S. full_name: Kollmann, S. last_name: Kollmann - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Guido full_name: Grundmeier, Guido id: '194' last_name: Grundmeier citation: ama: Bocchini A, Kollmann S, Gerstmann U, Schmidt WG, Grundmeier G. Phosphonic acid adsorption on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si23.svg" display="inline" id="d1e564"><mml:mi>α</mml:mi></mml:math>-Bi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si24.svg" display="inline" id="d1e569"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si25.svg" display="inline" id="d1e577"><mml:msub><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:math> surfaces. Surface Science. 2025;760. doi:10.1016/j.susc.2025.122776 apa: Bocchini, A., Kollmann, S., Gerstmann, U., Schmidt, W. G., & Grundmeier, G. (2025). Phosphonic acid adsorption on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si23.svg" display="inline" id="d1e564"><mml:mi>α</mml:mi></mml:math>-Bi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si24.svg" display="inline" id="d1e569"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si25.svg" display="inline" id="d1e577"><mml:msub><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:math> surfaces. Surface Science, 760, Article 122776. https://doi.org/10.1016/j.susc.2025.122776 bibtex: '@article{Bocchini_Kollmann_Gerstmann_Schmidt_Grundmeier_2025, title={Phosphonic acid adsorption on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si23.svg" display="inline" id="d1e564"><mml:mi>α</mml:mi></mml:math>-Bi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si24.svg" display="inline" id="d1e569"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si25.svg" display="inline" id="d1e577"><mml:msub><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:math> surfaces}, volume={760}, DOI={10.1016/j.susc.2025.122776}, number={122776}, journal={Surface Science}, publisher={Elsevier BV}, author={Bocchini, Adriana and Kollmann, S. and Gerstmann, Uwe and Schmidt, Wolf Gero and Grundmeier, Guido}, year={2025} }' chicago: Bocchini, Adriana, S. Kollmann, Uwe Gerstmann, Wolf Gero Schmidt, and Guido Grundmeier. “Phosphonic Acid Adsorption on <mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML" Altimg="si23.Svg" Display="inline" Id="d1e564"><mml:Mi>α</Mml:Mi></Mml:Math>-Bi<mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML" Altimg="si24.Svg" Display="inline" Id="d1e569"><mml:Msub><mml:Mrow/><mml:Mrow><mml:Mn>2</Mml:Mn></Mml:Mrow></Mml:Msub></Mml:Math>O<mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML" Altimg="si25.Svg" Display="inline" Id="d1e577"><mml:Msub><mml:Mrow/><mml:Mrow><mml:Mn>3</Mml:Mn></Mml:Mrow></Mml:Msub></Mml:Math> Surfaces.” Surface Science 760 (2025). https://doi.org/10.1016/j.susc.2025.122776. ieee: 'A. Bocchini, S. Kollmann, U. Gerstmann, W. G. Schmidt, and G. Grundmeier, “Phosphonic acid adsorption on <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si23.svg" display="inline" id="d1e564"><mml:mi>α</mml:mi></mml:math>-Bi<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si24.svg" display="inline" id="d1e569"><mml:msub><mml:mrow/><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:math>O<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si25.svg" display="inline" id="d1e577"><mml:msub><mml:mrow/><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:math> surfaces,” Surface Science, vol. 760, Art. no. 122776, 2025, doi: 10.1016/j.susc.2025.122776.' mla: Bocchini, Adriana, et al. “Phosphonic Acid Adsorption on <mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML" Altimg="si23.Svg" Display="inline" Id="d1e564"><mml:Mi>α</Mml:Mi></Mml:Math>-Bi<mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML" Altimg="si24.Svg" Display="inline" Id="d1e569"><mml:Msub><mml:Mrow/><mml:Mrow><mml:Mn>2</Mml:Mn></Mml:Mrow></Mml:Msub></Mml:Math>O<mml:Math Xmlns:Mml="http://Www.W3.Org/1998/Math/MathML" Altimg="si25.Svg" Display="inline" Id="d1e577"><mml:Msub><mml:Mrow/><mml:Mrow><mml:Mn>3</Mml:Mn></Mml:Mrow></Mml:Msub></Mml:Math> Surfaces.” Surface Science, vol. 760, 122776, Elsevier BV, 2025, doi:10.1016/j.susc.2025.122776. short: A. Bocchini, S. Kollmann, U. Gerstmann, W.G. Schmidt, G. Grundmeier, Surface Science 760 (2025). date_created: 2025-07-09T09:23:04Z date_updated: 2025-12-05T13:34:10Z department: - _id: '15' - _id: '2' - _id: '230' - _id: '295' - _id: '790' - _id: '302' - _id: '429' - _id: '35' - _id: '170' - _id: '27' doi: 10.1016/j.susc.2025.122776 intvolume: ' 760' language: - iso: eng main_file_link: - open_access: '1' url: https://doi.org/10.1016/j.susc.2025.122776 oa: '1' project: - _id: '52' name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing' - _id: '53' name: 'TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '55' name: 'TRR 142 - B: TRR 142 - Project Area B' - _id: '54' name: 'TRR 142 - A: TRR 142 - Project Area A' - _id: '168' name: 'TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*)' - _id: '166' name: 'TRR 142 - A11: TRR 142 - Subproject A11' publication: Surface Science publication_identifier: issn: - 0039-6028 publication_status: published publisher: Elsevier BV status: public title: Phosphonic acid adsorption on α-Bi2O3 surfaces type: journal_article user_id: '16199' volume: 760 year: '2025' ... --- _id: '61353' abstract: - lang: eng text: "Abstract\r\n Muonic hydrogen is an exotic atom where a muon instead of an electron is bound to a proton. The comparably high mass of the muon (≈ 207 · me\r\n \ ) has two important effects, (i) the reduced mass of the system becomes more important, and (ii) the muon is localized much closer to the nucleus. Thus, muonic hydrogen is not only excellently suitable for evaluating highly precise quantum electrodynamic (QED) calculations, but may also be used for assessing new approaches including finite nuclear size (FNS) effects to evaluate the proton structure and improve calculation schemes for the hyperfine splittings of many-particle systems, as e.g. to be implemented in density functional theory (DFT) software packages. Here, starting from Dirac’s equation we calculate the relativistic hyperfine splitting of the ground state and several excited states of muonic hydrogen analytically for different charge and magnetization models. The FNS related hyperfine shifts are compared with the differences between QED calculations and experimental measurements. This comparison also allows to unravel the role of the reduced mass, which is on one hand crucial in case of muonic atoms, but on the other hand is by no means well defined in relativistic quantum mechanics." article_number: '012001' author: - first_name: Katharina L. full_name: Franzke, Katharina L. last_name: Franzke - first_name: Wolf Gero full_name: Schmidt, Wolf Gero id: '468' last_name: Schmidt orcid: 0000-0002-2717-5076 - first_name: Uwe full_name: Gerstmann, Uwe id: '171' last_name: Gerstmann orcid: 0000-0002-4476-223X citation: ama: 'Franzke KL, Schmidt WG, Gerstmann U. Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen. Journal of Physics: Conference Series. 2025;3027(1). doi:10.1088/1742-6596/3027/1/012001' apa: 'Franzke, K. L., Schmidt, W. G., & Gerstmann, U. (2025). Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen. Journal of Physics: Conference Series, 3027(1), Article 012001. https://doi.org/10.1088/1742-6596/3027/1/012001' bibtex: '@article{Franzke_Schmidt_Gerstmann_2025, title={Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen}, volume={3027}, DOI={10.1088/1742-6596/3027/1/012001}, number={1012001}, journal={Journal of Physics: Conference Series}, publisher={IOP Publishing}, author={Franzke, Katharina L. and Schmidt, Wolf Gero and Gerstmann, Uwe}, year={2025} }' chicago: 'Franzke, Katharina L., Wolf Gero Schmidt, and Uwe Gerstmann. “Finite-Size and Relativistic Effects onto Hyperfine Interaction of Muonic Hydrogen.” Journal of Physics: Conference Series 3027, no. 1 (2025). https://doi.org/10.1088/1742-6596/3027/1/012001.' ieee: 'K. L. Franzke, W. G. Schmidt, and U. Gerstmann, “Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen,” Journal of Physics: Conference Series, vol. 3027, no. 1, Art. no. 012001, 2025, doi: 10.1088/1742-6596/3027/1/012001.' mla: 'Franzke, Katharina L., et al. “Finite-Size and Relativistic Effects onto Hyperfine Interaction of Muonic Hydrogen.” Journal of Physics: Conference Series, vol. 3027, no. 1, 012001, IOP Publishing, 2025, doi:10.1088/1742-6596/3027/1/012001.' short: 'K.L. Franzke, W.G. Schmidt, U. Gerstmann, Journal of Physics: Conference Series 3027 (2025).' date_created: 2025-09-18T11:17:05Z date_updated: 2025-12-05T13:32:45Z department: - _id: '15' - _id: '170' - _id: '295' - _id: '35' - _id: '230' - _id: '429' - _id: '27' - _id: '790' doi: 10.1088/1742-6596/3027/1/012001 intvolume: ' 3027' issue: '1' language: - iso: eng project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '54' name: TRR 142 - Project Area A - _id: '166' name: TRR 142 - Subproject A11 publication: 'Journal of Physics: Conference Series' publication_identifier: issn: - 1742-6588 - 1742-6596 publication_status: published publisher: IOP Publishing status: public title: Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen type: journal_article user_id: '16199' volume: 3027 year: '2025' ... --- _id: '60992' abstract: - lang: eng text: Non-Hermitian systems hosting exceptional points (EPs) exhibit enhanced sensitivity and unconventional mode dynamics. Going beyond isolated EPs, here we report on the existence of exceptional rings (ERs) in planar optical resonators with specific form of circular dichroism and TE-TM splitting. Such exceptional rings possess intriguing topologies as discussed earlier for condensed matter systems, but they remain virtually unexplored in presence of nonlinearity, for which our photonic platform is ideal. We find that when Kerr-type nonlinearity (or saturable gain) is introduced, the linear ER splits into two concentric ERs, with the larger-radius ring being a ring of third-order EPs. Transitioning from linear to nonlinear regime, we present a rigorous analysis of spectral topology and report enhanced and adjustable perturbation response in the nonlinear regime. Whereas certain features are specific to our system, the results on non-Hermitian spectral topology and nonlinearity-enhanced perturbation response are generic and equally relevant to a broad class of other nonlinear non-Hermitian systems, providing a universal framework for engineering ERs and EPs in nonlinear non-Hermitian systems. author: - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: 'Laura ' full_name: 'Ares Santos, Laura ' last_name: Ares Santos - first_name: Xuekai full_name: Ma, Xuekai id: '59416' last_name: Ma - first_name: Jan full_name: Sperling, Jan id: '75127' last_name: Sperling orcid: 0000-0002-5844-3205 - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 citation: ama: Wingenbach J, Ares Santos L, Ma X, Sperling J, Schumacher S. Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities. Arxiv. Published online 2025. doi:10.48550/ARXIV.2507.07099 apa: Wingenbach, J., Ares Santos, L., Ma, X., Sperling, J., & Schumacher, S. (2025). Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities. Arxiv. https://doi.org/10.48550/ARXIV.2507.07099 bibtex: '@article{Wingenbach_Ares Santos_Ma_Sperling_Schumacher_2025, title={Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities}, DOI={10.48550/ARXIV.2507.07099}, journal={Arxiv}, publisher={Arxiv}, author={Wingenbach, Jan and Ares Santos, Laura and Ma, Xuekai and Sperling, Jan and Schumacher, Stefan}, year={2025} }' chicago: Wingenbach, Jan, Laura Ares Santos, Xuekai Ma, Jan Sperling, and Stefan Schumacher. “Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities.” Arxiv, 2025. https://doi.org/10.48550/ARXIV.2507.07099. ieee: 'J. Wingenbach, L. Ares Santos, X. Ma, J. Sperling, and S. Schumacher, “Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities,” Arxiv, 2025, doi: 10.48550/ARXIV.2507.07099.' mla: Wingenbach, Jan, et al. “Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities.” Arxiv, Arxiv, 2025, doi:10.48550/ARXIV.2507.07099. short: J. Wingenbach, L. Ares Santos, X. Ma, J. Sperling, S. Schumacher, Arxiv (2025). date_created: 2025-08-25T11:15:22Z date_updated: 2025-12-05T13:55:48Z department: - _id: '15' - _id: '170' - _id: '297' - _id: '706' - _id: '705' - _id: '35' - _id: '230' - _id: '429' - _id: '27' doi: 10.48550/ARXIV.2507.07099 language: - iso: eng project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' - _id: '56' name: TRR 142 - Project Area C publication: Arxiv publisher: Arxiv status: public title: Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities type: journal_article user_id: '16199' year: '2025' ... --- _id: '62980' abstract: - lang: eng text: We introduce a new classification of multimode states with a fixed number of photons. This classification is based on the factorizability of homogeneous multivariate polynomials and is invariant under unitary transformations. The classes physically correspond to field excitations in terms of single and multiple photons, each of which is in an arbitrary irreducible superposition of quantized modes. We further show how the transitions between classes are rendered possible by photon addition, photon subtraction, and photon-projection nonlinearities. We explicitly put forward a design for a multilayer interferometer in which the states for different classes can be generated with state-of-the-art experimental techniques. Limitations of the proposed designs are analyzed using the introduced classification, providing a benchmark for the robustness of certain states and classes. article_number: '033062' author: - first_name: Denis A. full_name: Kopylov, Denis A. last_name: Kopylov - first_name: Christian full_name: Offen, Christian id: '85279' last_name: Offen orcid: 0000-0002-5940-8057 - first_name: Laura full_name: Ares, Laura last_name: Ares - first_name: Boris Edgar full_name: Wembe Moafo, Boris Edgar id: '95394' last_name: Wembe Moafo - first_name: Sina full_name: Ober-Blöbaum, Sina id: '16494' last_name: Ober-Blöbaum - first_name: Torsten full_name: Meier, Torsten id: '344' last_name: Meier orcid: 0000-0001-8864-2072 - first_name: Polina R. full_name: Sharapova, Polina R. id: '60286' last_name: Sharapova - first_name: Jan full_name: Sperling, Jan id: '75127' last_name: Sperling orcid: 0000-0002-5844-3205 citation: ama: Kopylov DA, Offen C, Ares L, et al. Multiphoton, multimode state classification for nonlinear optical circuits. Physical Review Research. 2025;7(3). doi:10.1103/sv6z-v1gk apa: Kopylov, D. A., Offen, C., Ares, L., Wembe Moafo, B. E., Ober-Blöbaum, S., Meier, T., Sharapova, P. R., & Sperling, J. (2025). Multiphoton, multimode state classification for nonlinear optical circuits. Physical Review Research, 7(3), Article 033062. https://doi.org/10.1103/sv6z-v1gk bibtex: '@article{Kopylov_Offen_Ares_Wembe Moafo_Ober-Blöbaum_Meier_Sharapova_Sperling_2025, title={Multiphoton, multimode state classification for nonlinear optical circuits}, volume={7}, DOI={10.1103/sv6z-v1gk}, number={3033062}, journal={Physical Review Research}, publisher={American Physical Society (APS)}, author={Kopylov, Denis A. and Offen, Christian and Ares, Laura and Wembe Moafo, Boris Edgar and Ober-Blöbaum, Sina and Meier, Torsten and Sharapova, Polina R. and Sperling, Jan}, year={2025} }' chicago: Kopylov, Denis A., Christian Offen, Laura Ares, Boris Edgar Wembe Moafo, Sina Ober-Blöbaum, Torsten Meier, Polina R. Sharapova, and Jan Sperling. “Multiphoton, Multimode State Classification for Nonlinear Optical Circuits.” Physical Review Research 7, no. 3 (2025). https://doi.org/10.1103/sv6z-v1gk. ieee: 'D. A. Kopylov et al., “Multiphoton, multimode state classification for nonlinear optical circuits,” Physical Review Research, vol. 7, no. 3, Art. no. 033062, 2025, doi: 10.1103/sv6z-v1gk.' mla: Kopylov, Denis A., et al. “Multiphoton, Multimode State Classification for Nonlinear Optical Circuits.” Physical Review Research, vol. 7, no. 3, 033062, American Physical Society (APS), 2025, doi:10.1103/sv6z-v1gk. short: D.A. Kopylov, C. Offen, L. Ares, B.E. Wembe Moafo, S. Ober-Blöbaum, T. Meier, P.R. Sharapova, J. Sperling, Physical Review Research 7 (2025). date_created: 2025-12-09T09:08:39Z date_updated: 2025-12-09T09:10:01Z department: - _id: '15' - _id: '569' - _id: '170' - _id: '293' - _id: '706' - _id: '636' - _id: '35' - _id: '230' - _id: '429' - _id: '623' doi: 10.1103/sv6z-v1gk intvolume: ' 7' issue: '3' language: - iso: eng project: - _id: '53' name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen' - _id: '56' name: TRR 142 - Project Area C - _id: '174' name: 'TRR 142 ; TP: C10: Erzeugung und Charakterisierung von Quantenlicht in nichtlinearen Systemen: Eine theoretische Analyse' - _id: '266' name: 'PhoQC: Photonisches Quantencomputing' publication: Physical Review Research publication_identifier: issn: - 2643-1564 publication_status: published publisher: American Physical Society (APS) status: public title: Multiphoton, multimode state classification for nonlinear optical circuits type: journal_article user_id: '16199' volume: 7 year: '2025' ...