[{"year":"2025","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","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.","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.","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","short":"K.L. Franzke, W.G. Schmidt, U. Gerstmann, Journal of Physics: Conference Series 3027 (2025).","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.","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} }"},"intvolume":" 3027","publication_status":"published","publication_identifier":{"issn":["1742-6588","1742-6596"]},"issue":"1","title":"Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen","doi":"10.1088/1742-6596/3027/1/012001","publisher":"IOP Publishing","date_updated":"2025-12-05T13:32:45Z","date_created":"2025-09-18T11:17:05Z","author":[{"full_name":"Franzke, Katharina L.","last_name":"Franzke","first_name":"Katharina L."},{"first_name":"Wolf Gero","full_name":"Schmidt, Wolf Gero","id":"468","last_name":"Schmidt","orcid":"0000-0002-2717-5076"},{"last_name":"Gerstmann","orcid":"0000-0002-4476-223X","id":"171","full_name":"Gerstmann, Uwe","first_name":"Uwe"}],"volume":3027,"abstract":[{"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.","lang":"eng"}],"status":"public","type":"journal_article","publication":"Journal of Physics: Conference Series","article_number":"012001","language":[{"iso":"eng"}],"project":[{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"},{"name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen","_id":"53"},{"name":"TRR 142 - Project Area A","_id":"54"},{"_id":"166","name":"TRR 142 - Subproject A11"}],"_id":"61353","user_id":"16199","department":[{"_id":"15"},{"_id":"170"},{"_id":"295"},{"_id":"35"},{"_id":"230"},{"_id":"429"},{"_id":"27"},{"_id":"790"}]},{"doi":"10.48550/ARXIV.2507.07099","title":"Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities","author":[{"first_name":"Jan","id":"69187","full_name":"Wingenbach, Jan","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","id":"75127","full_name":"Sperling, Jan","orcid":"0000-0002-5844-3205","last_name":"Sperling"},{"first_name":"Stefan","last_name":"Schumacher","orcid":"0000-0003-4042-4951","full_name":"Schumacher, Stefan","id":"27271"}],"date_created":"2025-08-25T11:15:22Z","publisher":"Arxiv","date_updated":"2025-12-05T13:55:48Z","citation":{"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} }","short":"J. Wingenbach, L. Ares Santos, X. Ma, J. Sperling, S. Schumacher, Arxiv (2025).","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.","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","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","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."},"year":"2025","language":[{"iso":"eng"}],"department":[{"_id":"15"},{"_id":"170"},{"_id":"297"},{"_id":"706"},{"_id":"705"},{"_id":"35"},{"_id":"230"},{"_id":"429"},{"_id":"27"}],"user_id":"16199","_id":"60992","project":[{"name":"Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"},{"_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"}],"status":"public","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."}],"publication":"Arxiv","type":"journal_article"},{"publisher":"Wiley","date_updated":"2025-12-05T14:18:27Z","author":[{"last_name":"Patra","full_name":"Patra, Atanu","first_name":"Atanu"},{"full_name":"Konrad, Paul","last_name":"Konrad","first_name":"Paul"},{"first_name":"Andreas","last_name":"Sperlich","full_name":"Sperlich, Andreas"},{"first_name":"Timur","full_name":"Biktagirov, Timur","id":"65612","last_name":"Biktagirov"},{"id":"468","full_name":"Schmidt, Wolf Gero","orcid":"0000-0002-2717-5076","last_name":"Schmidt","first_name":"Wolf Gero"},{"first_name":"Lesley","last_name":"Spencer","full_name":"Spencer, Lesley"},{"full_name":"Aharonovich, Igor","last_name":"Aharonovich","first_name":"Igor"},{"first_name":"Sven","last_name":"Höfling","full_name":"Höfling, Sven"},{"last_name":"Dyakonov","full_name":"Dyakonov, Vladimir","first_name":"Vladimir"}],"date_created":"2025-12-05T14:15:35Z","title":"Quantifying Spin Defect Density in hBN via Raman and Photoluminescence Analysis","doi":"10.1002/adfm.202517851","publication_identifier":{"issn":["1616-301X","1616-3028"]},"publication_status":"published","year":"2025","citation":{"apa":"Patra, A., Konrad, P., Sperlich, A., Biktagirov, T., Schmidt, W. G., Spencer, L., Aharonovich, I., Höfling, S., & Dyakonov, V. (2025). Quantifying Spin Defect Density in hBN via Raman and Photoluminescence Analysis. Advanced Functional Materials, Article e17851. https://doi.org/10.1002/adfm.202517851","short":"A. Patra, P. Konrad, A. Sperlich, T. Biktagirov, W.G. Schmidt, L. Spencer, I. Aharonovich, S. Höfling, V. Dyakonov, Advanced Functional Materials (2025).","bibtex":"@article{Patra_Konrad_Sperlich_Biktagirov_Schmidt_Spencer_Aharonovich_Höfling_Dyakonov_2025, title={Quantifying Spin Defect Density in hBN via Raman and Photoluminescence Analysis}, DOI={10.1002/adfm.202517851}, number={e17851}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Patra, Atanu and Konrad, Paul and Sperlich, Andreas and Biktagirov, Timur and Schmidt, Wolf Gero and Spencer, Lesley and Aharonovich, Igor and Höfling, Sven and Dyakonov, Vladimir}, year={2025} }","mla":"Patra, Atanu, et al. “Quantifying Spin Defect Density in HBN via Raman and Photoluminescence Analysis.” Advanced Functional Materials, e17851, Wiley, 2025, doi:10.1002/adfm.202517851.","chicago":"Patra, Atanu, Paul Konrad, Andreas Sperlich, Timur Biktagirov, Wolf Gero Schmidt, Lesley Spencer, Igor Aharonovich, Sven Höfling, and Vladimir Dyakonov. “Quantifying Spin Defect Density in HBN via Raman and Photoluminescence Analysis.” Advanced Functional Materials, 2025. https://doi.org/10.1002/adfm.202517851.","ieee":"A. Patra et al., “Quantifying Spin Defect Density in hBN via Raman and Photoluminescence Analysis,” Advanced Functional Materials, Art. no. e17851, 2025, doi: 10.1002/adfm.202517851.","ama":"Patra A, Konrad P, Sperlich A, et al. Quantifying Spin Defect Density in hBN via Raman and Photoluminescence Analysis. Advanced Functional Materials. Published online 2025. doi:10.1002/adfm.202517851"},"_id":"62926","project":[{"name":"Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"}],"department":[{"_id":"15"},{"_id":"170"},{"_id":"295"},{"_id":"35"},{"_id":"230"},{"_id":"27"}],"user_id":"16199","article_number":"e17851","language":[{"iso":"eng"}],"publication":"Advanced Functional Materials","type":"journal_article","abstract":[{"text":"Abstract\r\n \r\n Negatively charged boron vacancies () in hexagonal boron nitride (hBN) are emerging as promising solid‐state spin qubits due to their optical accessibility, structural simplicity, and compatibility with photonic platforms. However, quantifying the density of such defects in thin hBN flakes has remained elusive, limiting progress in device integration and reproducibility. Here, an all‐optical method is presented to quantify defect density in hBN by correlating Raman and photoluminescence (PL) signatures with irradiation fluence. Two defect‐induced Raman modes, D1 and D2, are identified and assigned them to vibrational modes of using polarization‐resolved Raman measurements and density functional theory (DFT) calculations. By adapting a numerical model originally developed for graphene, an empirical relationship linking Raman (D1,\r\n E\r\n 2g\r\n ) and PL intensities is established to absolute defect densities. This method is universally applicable across various irradiation types and uniquely suited for thin flakes, where conventional techniques fail. The approach enables accurate, direct, and non‐destructive quantification of spin defect densities down to 10\r\n 15\r\n  defects/cm\r\n 3\r\n , offering a powerful tool for optimizing and benchmarking hBN for quantum optical applications.\r\n ","lang":"eng"}],"status":"public"},{"publication":"Physical Review B","language":[{"iso":"eng"}],"year":"2025","issue":"24","title":"Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons","date_created":"2025-12-16T15:50:42Z","publisher":"American Physical Society (APS)","status":"public","type":"journal_article","article_number":"245304","user_id":"16199","department":[{"_id":"15"},{"_id":"170"},{"_id":"293"},{"_id":"297"},{"_id":"623"},{"_id":"429"},{"_id":"230"},{"_id":"35"},{"_id":"27"}],"project":[{"_id":"53","name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen"},{"name":"TRR 142 - Project Area A","_id":"54"},{"name":"TRR 142; TP A02: Nichtlineare Spektroskopie von Halbleiter-Nanostrukturen mit Quantenlicht","_id":"59"},{"name":"Hochleistungsrechner Noctua in Paderborn","_id":"445"},{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"},{"name":"PhoQC: Photonisches Quantencomputing","_id":"266"}],"_id":"63160","citation":{"bibtex":"@article{Rose_Schumacher_Meier_2025, title={Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons}, volume={112}, DOI={10.1103/528f-7smh}, number={24245304}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Rose, Hendrik and Schumacher, Stefan and Meier, Torsten}, year={2025} }","mla":"Rose, Hendrik, et al. “Microscopic Approach to the Quantized Light-Matter Interaction in Semiconductor Nanostructures: Complex Coupled Dynamics of Excitons, Biexcitons, and Photons.” Physical Review B, vol. 112, no. 24, 245304, American Physical Society (APS), 2025, doi:10.1103/528f-7smh.","short":"H. Rose, S. Schumacher, T. Meier, Physical Review B 112 (2025).","apa":"Rose, H., Schumacher, S., & Meier, T. (2025). Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons. Physical Review B, 112(24), Article 245304. https://doi.org/10.1103/528f-7smh","ieee":"H. Rose, S. Schumacher, and T. Meier, “Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons,” Physical Review B, vol. 112, no. 24, Art. no. 245304, 2025, doi: 10.1103/528f-7smh.","chicago":"Rose, Hendrik, Stefan Schumacher, and Torsten Meier. “Microscopic Approach to the Quantized Light-Matter Interaction in Semiconductor Nanostructures: Complex Coupled Dynamics of Excitons, Biexcitons, and Photons.” Physical Review B 112, no. 24 (2025). https://doi.org/10.1103/528f-7smh.","ama":"Rose H, Schumacher S, Meier T. Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons. Physical Review B. 2025;112(24). doi:10.1103/528f-7smh"},"intvolume":" 112","publication_status":"published","publication_identifier":{"issn":["2469-9950","2469-9969"]},"doi":"10.1103/528f-7smh","author":[{"first_name":"Hendrik","full_name":"Rose, Hendrik","id":"55958","last_name":"Rose","orcid":"0000-0002-3079-5428"},{"full_name":"Schumacher, Stefan","id":"27271","orcid":"0000-0003-4042-4951","last_name":"Schumacher","first_name":"Stefan"},{"first_name":"Torsten","id":"344","full_name":"Meier, Torsten","last_name":"Meier","orcid":"0000-0001-8864-2072"}],"volume":112,"date_updated":"2025-12-16T15:52:55Z"},{"has_accepted_license":"1","publication_identifier":{"issn":["2475-9953"]},"publication_status":"published","intvolume":" 9","citation":{"chicago":"Bocchini, Adriana, Michael Rüsing, Laura Bollmers, Sebastian Lengeling, Philipp Mues, Laura Padberg, Uwe Gerstmann, Christine Silberhorn, Christof Eigner, and Wolf Gero Schmidt. “Mg Dopants in Lithium Niobate: Defect Models and Impact on Domain Inversion.” Physical Review Materials 9, no. 7 (2025). https://doi.org/10.1103/5wz1-bjyr.","ieee":"A. Bocchini et al., “Mg dopants in lithium niobate: Defect models and impact on domain inversion,” Physical Review Materials, vol. 9, no. 7, Art. no. 074402, 2025, doi: 10.1103/5wz1-bjyr.","ama":"Bocchini A, Rüsing M, Bollmers L, et al. Mg dopants in lithium niobate: Defect models and impact on domain inversion. Physical Review Materials. 2025;9(7). doi:10.1103/5wz1-bjyr","apa":"Bocchini, A., Rüsing, M., Bollmers, L., Lengeling, S., Mues, P., Padberg, L., Gerstmann, U., Silberhorn, C., Eigner, C., & Schmidt, W. G. (2025). Mg dopants in lithium niobate: Defect models and impact on domain inversion. Physical Review Materials, 9(7), Article 074402. https://doi.org/10.1103/5wz1-bjyr","bibtex":"@article{Bocchini_Rüsing_Bollmers_Lengeling_Mues_Padberg_Gerstmann_Silberhorn_Eigner_Schmidt_2025, title={Mg dopants in lithium niobate: Defect models and impact on domain inversion}, volume={9}, DOI={10.1103/5wz1-bjyr}, number={7074402}, journal={Physical Review Materials}, publisher={American Physical Society (APS)}, author={Bocchini, Adriana and Rüsing, Michael and Bollmers, Laura and Lengeling, Sebastian and Mues, Philipp and Padberg, Laura and Gerstmann, Uwe and Silberhorn, Christine and Eigner, Christof and Schmidt, Wolf Gero}, year={2025} }","mla":"Bocchini, Adriana, et al. “Mg Dopants in Lithium Niobate: Defect Models and Impact on Domain Inversion.” Physical Review Materials, vol. 9, no. 7, 074402, American Physical Society (APS), 2025, doi:10.1103/5wz1-bjyr.","short":"A. Bocchini, M. Rüsing, L. Bollmers, S. Lengeling, P. Mues, L. Padberg, U. Gerstmann, C. Silberhorn, C. Eigner, W.G. Schmidt, Physical Review Materials 9 (2025)."},"oa":"1","date_updated":"2026-03-17T17:50:06Z","volume":9,"author":[{"full_name":"Bocchini, Adriana","id":"58349","last_name":"Bocchini","orcid":"0000-0002-2134-3075","first_name":"Adriana"},{"first_name":"Michael","id":"22501","full_name":"Rüsing, Michael","orcid":"0000-0003-4682-4577","last_name":"Rüsing"},{"full_name":"Bollmers, Laura","id":"61375","last_name":"Bollmers","first_name":"Laura"},{"first_name":"Sebastian","id":"44373","full_name":"Lengeling, Sebastian","last_name":"Lengeling"},{"first_name":"Philipp","orcid":"0000-0003-0643-7636","last_name":"Mues","id":"49772","full_name":"Mues, Philipp"},{"first_name":"Laura","full_name":"Padberg, Laura","id":"40300","last_name":"Padberg"},{"first_name":"Uwe","id":"171","full_name":"Gerstmann, Uwe","last_name":"Gerstmann","orcid":"0000-0002-4476-223X"},{"last_name":"Silberhorn","full_name":"Silberhorn, Christine","id":"26263","first_name":"Christine"},{"id":"13244","full_name":"Eigner, Christof","last_name":"Eigner","orcid":"https://orcid.org/0000-0002-5693-3083","first_name":"Christof"},{"first_name":"Wolf Gero","orcid":"0000-0002-2717-5076","last_name":"Schmidt","id":"468","full_name":"Schmidt, Wolf Gero"}],"doi":"10.1103/5wz1-bjyr","main_file_link":[{"url":"https://link.aps.org/doi/10.1103/5wz1-bjyr","open_access":"1"}],"type":"journal_article","status":"public","_id":"60566","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"},{"name":"TRR 142 - B07: TRR 142 - Polaronen-Einfluss auf die optischen Eigenschaften von Lithiumniobat (B07*)","_id":"168"},{"name":"TRR 142 - A11: TRR 142 - Subproject A11","_id":"166"}],"department":[{"_id":"15"},{"_id":"623"},{"_id":"295"},{"_id":"790"},{"_id":"288"},{"_id":"230"},{"_id":"429"},{"_id":"35"},{"_id":"170"},{"_id":"169"},{"_id":"27"}],"user_id":"22501","article_number":"074402","file_date_updated":"2025-07-10T06:43:34Z","issue":"7","year":"2025","publisher":"American Physical Society (APS)","date_created":"2025-07-09T09:13:24Z","title":"Mg dopants in lithium niobate: Defect models and impact on domain inversion","publication":"Physical Review Materials","file":[{"date_created":"2025-07-09T09:18:45Z","creator":"adrianab","date_updated":"2025-07-10T06:43:34Z","access_level":"open_access","file_name":"Mg_dopants_LN_PRM.pdf","file_id":"60567","file_size":4175120,"content_type":"application/pdf","relation":"main_file"}],"ddc":["530"],"language":[{"iso":"eng"}]},{"title":"Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia","doi":"10.1145/3731599.3767570","publisher":"ACM","date_updated":"2026-03-24T09:06:33Z","date_created":"2026-03-24T09:05:22Z","author":[{"first_name":"Kaan","last_name":"Olgu","full_name":"Olgu, Kaan"},{"last_name":"Kenter","full_name":"Kenter, Tobias","id":"3145","first_name":"Tobias"},{"first_name":"Jose","full_name":"Nunez-Yanez, Jose","last_name":"Nunez-Yanez"},{"first_name":"Simon","full_name":"McIntosh-Smith, Simon","last_name":"McIntosh-Smith"},{"full_name":"Deakin, Tom","last_name":"Deakin","first_name":"Tom"}],"year":"2025","citation":{"ieee":"K. Olgu, T. Kenter, J. Nunez-Yanez, S. McIntosh-Smith, and T. Deakin, “Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia,” 2025, doi: 10.1145/3731599.3767570.","chicago":"Olgu, Kaan, Tobias Kenter, Jose Nunez-Yanez, Simon McIntosh-Smith, and Tom Deakin. “Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia.” In Proceedings of the SC ’25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis. ACM, 2025. https://doi.org/10.1145/3731599.3767570.","ama":"Olgu K, Kenter T, Nunez-Yanez J, McIntosh-Smith S, Deakin T. Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia. In: Proceedings of the SC ’25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis. ACM; 2025. doi:10.1145/3731599.3767570","mla":"Olgu, Kaan, et al. “Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia.” Proceedings of the SC ’25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis, ACM, 2025, doi:10.1145/3731599.3767570.","short":"K. Olgu, T. Kenter, J. Nunez-Yanez, S. McIntosh-Smith, T. Deakin, in: Proceedings of the SC ’25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis, ACM, 2025.","bibtex":"@inproceedings{Olgu_Kenter_Nunez-Yanez_McIntosh-Smith_Deakin_2025, title={Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia}, DOI={10.1145/3731599.3767570}, booktitle={Proceedings of the SC ’25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis}, publisher={ACM}, author={Olgu, Kaan and Kenter, Tobias and Nunez-Yanez, Jose and McIntosh-Smith, Simon and Deakin, Tom}, year={2025} }","apa":"Olgu, K., Kenter, T., Nunez-Yanez, J., McIntosh-Smith, S., & Deakin, T. (2025). Towards Efficient Load Balancing BFS on GPUs: One Code for AMD, Intel & Nvidia. Proceedings of the SC ’25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis. https://doi.org/10.1145/3731599.3767570"},"publication_status":"published","language":[{"iso":"eng"}],"_id":"65102","project":[{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"}],"department":[{"_id":"27"},{"_id":"518"}],"user_id":"3145","abstract":[{"lang":"eng","text":"Efficient graph processing is essential for a wide range of applications. Scalability and memory access patterns are still a challenge, especially with the Breadth-First Search algorithm. This work focuses on leveraging HPC systems with multiple GPUs available in a single node with peer-to-peer functionality of the Intel oneAPI implementation of SYCL. We propose three GPU-based load-balancing methods: work-group localisation for efficient data access, even workload distribution for higher GPU occupancy, and a hybrid strided-access approach for heuristic balancing. These methods ensure performance, portability, and productivity with a unified codebase. Our proposed methodologies outperform state-of-the-art single-GPU implementations based on CUDA on synthetic RMAT graphs. We analysed BFS performance across NVIDIA A100, Intel Max 1550, and AMD MI300X GPUs, achieving a peak performance of 153.27 GTEPS on an RMAT25-64 graph using 8 GPUs on the NVIDIA A100. Furthermore, our work demonstrates the capability to handle RMAT graphs up to scale 29, achieving superior performance on synthetic graphs and competitive results on real-world datasets."}],"status":"public","publication":"Proceedings of the SC '25 Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis","type":"conference"},{"title":"Otus Supercomputer","date_created":"2025-12-09T09:11:04Z","publisher":"Paderborn Center for Parallel Computing (PC2)","year":"2025","language":[{"iso":"eng"}],"ddc":["004"],"keyword":["Otus","Supercomputer","FPGA","PC2","Paderborn Center for Parallel Computing","Noctua 2","HPC"],"file":[{"file_name":"2512.07401v1.pdf","access_level":"open_access","file_id":"62982","file_size":4535595,"date_created":"2025-12-09T09:19:12Z","creator":"deffel","date_updated":"2026-03-25T11:50:30Z","relation":"main_file","content_type":"application/pdf"}],"abstract":[{"lang":"eng","text":"Otus is a high-performance computing cluster that was launched in 2025 and is operated by the Paderborn Center for Parallel Computing (PC2) at Paderborn University in Germany. The system is part of the National High Performance Computing (NHR) initiative. Otus complements the previous supercomputer Noctua 2, offering approximately twice the computing power while retaining the three node types that were characteristic of Noctua 2: 1) CPU compute nodes with different memory capacities, 2) high-end GPU nodes, and 3) HPC-grade FPGA nodes. On the Top500 list, which ranks the 500 most powerful supercomputers in the world, Otus is in position 164 with the CPU partition and in position 255 with the GPU partition (June 2025). On the Green500 list, ranking the 500 most energy-efficient supercomputers in the world, Otus is in position 5 with the GPU partition (June 2025).\r\n\r\n\r\nThis article provides a comprehensive overview of the system in terms of its hardware, software, system integration, and its overall integration into the data center building to ensure energy-efficient operation. The article aims to provide unique insights for scientists using the system and for other centers operating HPC clusters. The article will be continuously updated to reflect the latest system setup and measurements. "}],"report_number":"PC2TR-2025-1","doi":"10.48550/ARXIV.2512.07401","author":[{"full_name":"Ehtesabi, Sadaf","id":"116116","last_name":"Ehtesabi","first_name":"Sadaf"},{"id":"114619","full_name":"Hossain, Manoar","orcid":"https://orcid.org/0000-0002-0737-7981","last_name":"Hossain","first_name":"Manoar"},{"first_name":"Tobias","id":"3145","full_name":"Kenter, Tobias","last_name":"Kenter"},{"first_name":"Andreas","id":"15275","full_name":"Krawinkel, Andreas","last_name":"Krawinkel"},{"first_name":"Lukas","last_name":"Ostermann","full_name":"Ostermann, Lukas","id":"69976"},{"orcid":"0000-0001-5728-9982","last_name":"Plessl","id":"16153","full_name":"Plessl, Christian","first_name":"Christian"},{"first_name":"Heinrich","last_name":"Riebler","id":"8961","full_name":"Riebler, Heinrich"},{"first_name":"Stefan","last_name":"Rohde","id":"34009","full_name":"Rohde, Stefan"},{"first_name":"Robert","orcid":"0000-0002-6268-5397","last_name":"Schade","full_name":"Schade, Robert","id":"75963"},{"last_name":"Schwarz","full_name":"Schwarz, Michael","id":"5312","first_name":"Michael"},{"first_name":"Jens","last_name":"Simon","full_name":"Simon, Jens","id":"15273"},{"first_name":"Nils","last_name":"Winnwa","id":"61189","full_name":"Winnwa, Nils"},{"id":"23522","full_name":"Wiens, Alex","orcid":"0000-0003-1764-9773","last_name":"Wiens","first_name":"Alex"},{"id":"77439","full_name":"Wu, Xin","last_name":"Wu","first_name":"Xin"}],"volume":1,"oa":"1","date_updated":"2026-03-25T11:50:31Z","citation":{"bibtex":"@book{Ehtesabi_Hossain_Kenter_Krawinkel_Ostermann_Plessl_Riebler_Rohde_Schade_Schwarz_et al._2025, place={Paderborn}, series={PC2 Tech­nic­al Re­port Series}, title={Otus Supercomputer}, volume={1}, DOI={10.48550/ARXIV.2512.07401}, publisher={Paderborn Center for Parallel Computing (PC2)}, author={Ehtesabi, Sadaf and Hossain, Manoar and Kenter, Tobias and Krawinkel, Andreas and Ostermann, Lukas and Plessl, Christian and Riebler, Heinrich and Rohde, Stefan and Schade, Robert and Schwarz, Michael and et al.}, year={2025}, collection={PC2 Tech­nic­al Re­port Series} }","short":"S. Ehtesabi, M. Hossain, T. Kenter, A. Krawinkel, L. Ostermann, C. Plessl, H. Riebler, S. Rohde, R. Schade, M. Schwarz, J. Simon, N. Winnwa, A. Wiens, X. Wu, Otus Supercomputer, Paderborn Center for Parallel Computing (PC2), Paderborn, 2025.","mla":"Ehtesabi, Sadaf, et al. Otus Supercomputer. Paderborn Center for Parallel Computing (PC2), 2025, doi:10.48550/ARXIV.2512.07401.","apa":"Ehtesabi, S., Hossain, M., Kenter, T., Krawinkel, A., Ostermann, L., Plessl, C., Riebler, H., Rohde, S., Schade, R., Schwarz, M., Simon, J., Winnwa, N., Wiens, A., & Wu, X. (2025). Otus Supercomputer (Vol. 1). Paderborn Center for Parallel Computing (PC2). https://doi.org/10.48550/ARXIV.2512.07401","ieee":"S. Ehtesabi et al., Otus Supercomputer, vol. 1. Paderborn: Paderborn Center for Parallel Computing (PC2), 2025.","chicago":"Ehtesabi, Sadaf, Manoar Hossain, Tobias Kenter, Andreas Krawinkel, Lukas Ostermann, Christian Plessl, Heinrich Riebler, et al. Otus Supercomputer. Vol. 1. PC2 Tech­nic­al Re­port Series. Paderborn: Paderborn Center for Parallel Computing (PC2), 2025. https://doi.org/10.48550/ARXIV.2512.07401.","ama":"Ehtesabi S, Hossain M, Kenter T, et al. Otus Supercomputer. Vol 1. Paderborn Center for Parallel Computing (PC2); 2025. doi:10.48550/ARXIV.2512.07401"},"intvolume":" 1","page":"33","place":"Paderborn","publication_status":"published","has_accepted_license":"1","file_date_updated":"2026-03-25T11:50:30Z","series_title":"PC2 Tech­nic­al Re­port Series","user_id":"23522","department":[{"_id":"27"},{"_id":"518"}],"_id":"62981","status":"public","type":"report"},{"abstract":[{"text":"We present a novel approach to characterize and quantify microheterogeneity and microphase separation in computer simulations of complex liquid mixtures. Our post-processing method is based on local density fluctuations of the different constituents in sampling spheres of varying size. It can be easily applied to both molecular dynamics (MD) and Monte Carlo (MC) simulations, including periodic boundary conditions. Multidimensional correlation of the density distributions yields a clear picture of the domain formation due to the subtle balance of different interactions. We apply our approach to the example of force field molecular dynamics simulations of imidazolium-based ionic liquids with different side chain lengths at different temperatures, namely 1-ethyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride, which are known to form distinct liquid domains. We put the results into the context of existing microheterogeneity analyses and demonstrate the advantages and sensitivity of our novel method. Furthermore, we show how to estimate the configuration entropy from our analysis, and we investigate voids in the system. The analysis has been implemented into our program package TRAVIS and is thus available as free software.","lang":"eng"}],"status":"public","type":"journal_article","publication":"Entropy","article_number":"322","language":[{"iso":"eng"}],"project":[{"name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"}],"_id":"53474","user_id":"24135","department":[{"_id":"27"},{"_id":"518"},{"_id":"803"}],"year":"2024","citation":{"ieee":"M. Lass, T. Kenter, C. Plessl, and M. Brehm, “Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations,” Entropy, vol. 26, no. 4, Art. no. 322, 2024, doi: 10.3390/e26040322.","chicago":"Lass, Michael, Tobias Kenter, Christian Plessl, and Martin Brehm. “Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations.” Entropy 26, no. 4 (2024). https://doi.org/10.3390/e26040322.","ama":"Lass M, Kenter T, Plessl C, Brehm M. Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations. Entropy. 2024;26(4). doi:10.3390/e26040322","apa":"Lass, M., Kenter, T., Plessl, C., & Brehm, M. (2024). Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations. Entropy, 26(4), Article 322. https://doi.org/10.3390/e26040322","mla":"Lass, Michael, et al. “Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations.” Entropy, vol. 26, no. 4, 322, MDPI AG, 2024, doi:10.3390/e26040322.","short":"M. Lass, T. Kenter, C. Plessl, M. Brehm, Entropy 26 (2024).","bibtex":"@article{Lass_Kenter_Plessl_Brehm_2024, title={Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations}, volume={26}, DOI={10.3390/e26040322}, number={4322}, journal={Entropy}, publisher={MDPI AG}, author={Lass, Michael and Kenter, Tobias and Plessl, Christian and Brehm, Martin}, year={2024} }"},"intvolume":" 26","publication_status":"published","publication_identifier":{"issn":["1099-4300"]},"issue":"4","title":"Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations","doi":"10.3390/e26040322","publisher":"MDPI AG","date_updated":"2024-04-12T18:34:32Z","date_created":"2024-04-12T18:31:39Z","author":[{"last_name":"Lass","orcid":"0000-0002-5708-7632","id":"24135","full_name":"Lass, Michael","first_name":"Michael"},{"last_name":"Kenter","full_name":"Kenter, Tobias","id":"3145","first_name":"Tobias"},{"full_name":"Plessl, Christian","id":"16153","orcid":"0000-0001-5728-9982","last_name":"Plessl","first_name":"Christian"},{"first_name":"Martin","last_name":"Brehm","full_name":"Brehm, Martin","id":"100167"}],"volume":26},{"file_date_updated":"2024-04-26T08:35:17Z","article_type":"original","department":[{"_id":"27"},{"_id":"518"}],"user_id":"8961","_id":"53663","project":[{"_id":"52","name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing"}],"status":"public","type":"journal_article","doi":"10.17815/jlsrf-8-187 ","volume":9,"author":[{"id":"90082","full_name":"Bauer, Carsten","last_name":"Bauer","first_name":"Carsten"},{"last_name":"Kenter","full_name":"Kenter, Tobias","id":"3145","first_name":"Tobias"},{"first_name":"Michael","id":"24135","full_name":"Lass, Michael","last_name":"Lass","orcid":"0000-0002-5708-7632"},{"first_name":"Lukas","last_name":"Mazur","orcid":" 0000-0001-6304-7082","id":"90492","full_name":"Mazur, Lukas"},{"first_name":"Marius","last_name":"Meyer","full_name":"Meyer, Marius","id":"40778"},{"first_name":"Holger","id":"15272","full_name":"Nitsche, Holger","last_name":"Nitsche"},{"id":"8961","full_name":"Riebler, Heinrich","last_name":"Riebler","first_name":"Heinrich"},{"first_name":"Robert","last_name":"Schade","orcid":"0000-0002-6268-5397","id":"75963","full_name":"Schade, Robert"},{"full_name":"Schwarz, Michael","id":"5312","last_name":"Schwarz","first_name":"Michael"},{"first_name":"Nils","last_name":"Winnwa","id":"61189","full_name":"Winnwa, Nils"},{"first_name":"Alex","id":"23522","full_name":"Wiens, Alex","orcid":"0000-0003-1764-9773","last_name":"Wiens"},{"last_name":"Wu","id":"77439","full_name":"Wu, Xin","first_name":"Xin"},{"first_name":"Christian","orcid":"0000-0001-5728-9982","last_name":"Plessl","id":"16153","full_name":"Plessl, Christian"},{"id":"15273","full_name":"Simon, Jens","last_name":"Simon","first_name":"Jens"}],"date_updated":"2024-04-26T08:44:30Z","oa":"1","intvolume":" 9","citation":{"apa":"Bauer, C., Kenter, T., Lass, M., Mazur, L., Meyer, M., Nitsche, H., Riebler, H., Schade, R., Schwarz, M., Winnwa, N., Wiens, A., Wu, X., Plessl, C., & Simon, J. (2024). Noctua 2 Supercomputer. Journal of Large-Scale Research Facilities, 9. https://doi.org/10.17815/jlsrf-8-187 ","mla":"Bauer, Carsten, et al. “Noctua 2 Supercomputer.” Journal of Large-Scale Research Facilities, vol. 9, 2024, doi:10.17815/jlsrf-8-187 .","short":"C. Bauer, T. Kenter, M. Lass, L. Mazur, M. Meyer, H. Nitsche, H. Riebler, R. Schade, M. Schwarz, N. Winnwa, A. Wiens, X. Wu, C. Plessl, J. Simon, Journal of Large-Scale Research Facilities 9 (2024).","bibtex":"@article{Bauer_Kenter_Lass_Mazur_Meyer_Nitsche_Riebler_Schade_Schwarz_Winnwa_et al._2024, title={Noctua 2 Supercomputer}, volume={9}, DOI={10.17815/jlsrf-8-187 }, journal={Journal of large-scale research facilities}, author={Bauer, Carsten and Kenter, Tobias and Lass, Michael and Mazur, Lukas and Meyer, Marius and Nitsche, Holger and Riebler, Heinrich and Schade, Robert and Schwarz, Michael and Winnwa, Nils and et al.}, year={2024} }","chicago":"Bauer, Carsten, Tobias Kenter, Michael Lass, Lukas Mazur, Marius Meyer, Holger Nitsche, Heinrich Riebler, et al. “Noctua 2 Supercomputer.” Journal of Large-Scale Research Facilities 9 (2024). https://doi.org/10.17815/jlsrf-8-187 .","ieee":"C. Bauer et al., “Noctua 2 Supercomputer,” Journal of large-scale research facilities, vol. 9, 2024, doi: 10.17815/jlsrf-8-187 .","ama":"Bauer C, Kenter T, Lass M, et al. Noctua 2 Supercomputer. Journal of large-scale research facilities. 2024;9. doi:10.17815/jlsrf-8-187 "},"has_accepted_license":"1","publication_status":"published","language":[{"iso":"eng"}],"keyword":["Noctua 2","Supercomputer","FPGA","PC2","Paderborn Center for Parallel Computing"],"ddc":["004"],"file":[{"date_created":"2024-04-26T07:30:20Z","creator":"deffel","date_updated":"2024-04-26T08:35:17Z","file_name":"Noctua2_Supercomputer.pdf","file_id":"53664","access_level":"open_access","file_size":3825480,"content_type":"application/pdf","relation":"main_file"}],"abstract":[{"text":"Noctua 2 is a supercomputer operated at the Paderborn Center for Parallel Computing (PC2) at Paderborn University in Germany. Noctua 2 was inaugurated in 2022 and is an Atos BullSequana XH2000 system. It consists mainly of three node types: 1) CPU Compute nodes with AMD EPYC processors in different main memory configurations, 2) GPU nodes with NVIDIA A100 GPUs, and 3) FPGA nodes with Xilinx Alveo U280 and Intel Stratix 10 FPGA cards. While CPUs and GPUs are known off-the-shelf components in HPC systems, the operation of a large number of FPGA cards from different vendors and a dedicated FPGA-to-FPGA network are unique characteristics of Noctua 2. This paper describes in detail the overall setup of Noctua 2 and gives insights into the operation of the cluster from a hardware, software and facility perspective.","lang":"eng"}],"publication":"Journal of large-scale research facilities","title":"Noctua 2 Supercomputer","date_created":"2024-04-26T07:39:41Z","year":"2024"},{"year":"2024","issue":"7","title":"Optical Stark effect in type-II semiconductor heterostructures","publisher":"American Physical Society (APS)","date_created":"2024-07-15T09:47:27Z","publication":"Physical Review B","language":[{"iso":"eng"}],"intvolume":" 109","citation":{"bibtex":"@article{Schäfer_Trautmann_Ngo_Steiner_Fuchs_Volz_Dobener_Stein_Meier_Chatterjee_2024, title={Optical Stark effect in type-II semiconductor heterostructures}, volume={109}, DOI={10.1103/physrevb.109.075301}, number={7075301}, journal={Physical Review B}, publisher={American Physical Society (APS)}, author={Schäfer, F. and Trautmann, A. and Ngo, C. and Steiner, J. T. and Fuchs, C. and Volz, K. and Dobener, F. and Stein, M. and Meier, Torsten and Chatterjee, S.}, year={2024} }","mla":"Schäfer, F., et al. “Optical Stark Effect in Type-II Semiconductor Heterostructures.” Physical Review B, vol. 109, no. 7, 075301, American Physical Society (APS), 2024, doi:10.1103/physrevb.109.075301.","short":"F. Schäfer, A. Trautmann, C. Ngo, J.T. Steiner, C. Fuchs, K. Volz, F. Dobener, M. Stein, T. Meier, S. Chatterjee, Physical Review B 109 (2024).","apa":"Schäfer, F., Trautmann, A., Ngo, C., Steiner, J. T., Fuchs, C., Volz, K., Dobener, F., Stein, M., Meier, T., & Chatterjee, S. (2024). Optical Stark effect in type-II semiconductor heterostructures. Physical Review B, 109(7), Article 075301. https://doi.org/10.1103/physrevb.109.075301","ieee":"F. Schäfer et al., “Optical Stark effect in type-II semiconductor heterostructures,” Physical Review B, vol. 109, no. 7, Art. no. 075301, 2024, doi: 10.1103/physrevb.109.075301.","chicago":"Schäfer, F., A. Trautmann, C. Ngo, J. T. Steiner, C. Fuchs, K. Volz, F. Dobener, M. Stein, Torsten Meier, and S. Chatterjee. “Optical Stark Effect in Type-II Semiconductor Heterostructures.” Physical Review B 109, no. 7 (2024). https://doi.org/10.1103/physrevb.109.075301.","ama":"Schäfer F, Trautmann A, Ngo C, et al. Optical Stark effect in type-II semiconductor heterostructures. Physical Review B. 2024;109(7). doi:10.1103/physrevb.109.075301"},"publication_identifier":{"issn":["2469-9950","2469-9969"]},"publication_status":"published","doi":"10.1103/physrevb.109.075301","date_updated":"2024-07-15T09:49:41Z","volume":109,"author":[{"last_name":"Schäfer","full_name":"Schäfer, F.","first_name":"F."},{"first_name":"A.","full_name":"Trautmann, A.","last_name":"Trautmann"},{"full_name":"Ngo, C.","last_name":"Ngo","first_name":"C."},{"first_name":"J. T.","last_name":"Steiner","full_name":"Steiner, J. T."},{"full_name":"Fuchs, C.","last_name":"Fuchs","first_name":"C."},{"first_name":"K.","last_name":"Volz","full_name":"Volz, K."},{"first_name":"F.","last_name":"Dobener","full_name":"Dobener, F."},{"last_name":"Stein","full_name":"Stein, M.","first_name":"M."},{"first_name":"Torsten","last_name":"Meier","orcid":"0000-0001-8864-2072","full_name":"Meier, Torsten","id":"344"},{"first_name":"S.","last_name":"Chatterjee","full_name":"Chatterjee, S."}],"status":"public","type":"journal_article","article_number":"075301","_id":"55267","project":[{"name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"},{"grant_number":"231447078","_id":"53","name":"TRR 142: TRR 142 - Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen"},{"grant_number":"231447078","name":"TRR 142 - A10: TRR 142 - Nichtlinearitäten von atomar dünnen Übergangsmetall-Dichalkogeniden in starken Feldern (A10)","_id":"165"}],"department":[{"_id":"15"},{"_id":"170"},{"_id":"293"},{"_id":"35"},{"_id":"230"},{"_id":"429"},{"_id":"27"}],"user_id":"16199"},{"citation":{"ieee":"M. Meyer, T. Kenter, L. Petrica, K. O’Brien, M. Blott, and C. Plessl, “Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL,” in Lecture Notes in Computer Science, Cham: Springer Nature Switzerland, 2024.","chicago":"Meyer, Marius, Tobias Kenter, Lucian Petrica, Kenneth O’Brien, Michaela Blott, and Christian Plessl. “Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL.” In Lecture Notes in Computer Science. Cham: Springer Nature Switzerland, 2024. https://doi.org/10.1007/978-3-031-69766-1_9.","ama":"Meyer M, Kenter T, Petrica L, O’Brien K, Blott M, Plessl C. Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL. In: Lecture Notes in Computer Science. Springer Nature Switzerland; 2024. doi:10.1007/978-3-031-69766-1_9","apa":"Meyer, M., Kenter, T., Petrica, L., O’Brien, K., Blott, M., & Plessl, C. (2024). Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL. In Lecture Notes in Computer Science. Springer Nature Switzerland. https://doi.org/10.1007/978-3-031-69766-1_9","mla":"Meyer, Marius, et al. “Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL.” Lecture Notes in Computer Science, Springer Nature Switzerland, 2024, doi:10.1007/978-3-031-69766-1_9.","bibtex":"@inbook{Meyer_Kenter_Petrica_O’Brien_Blott_Plessl_2024, place={Cham}, title={Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL}, DOI={10.1007/978-3-031-69766-1_9}, booktitle={Lecture Notes in Computer Science}, publisher={Springer Nature Switzerland}, author={Meyer, Marius and Kenter, Tobias and Petrica, Lucian and O’Brien, Kenneth and Blott, Michaela and Plessl, Christian}, year={2024} }","short":"M. Meyer, T. Kenter, L. Petrica, K. O’Brien, M. Blott, C. Plessl, in: Lecture Notes in Computer Science, Springer Nature Switzerland, Cham, 2024."},"year":"2024","place":"Cham","publication_status":"published","publication_identifier":{"isbn":["9783031697654","9783031697661"],"issn":["0302-9743","1611-3349"]},"quality_controlled":"1","main_file_link":[{"open_access":"1"}],"doi":"10.1007/978-3-031-69766-1_9","title":"Optimizing Communication for Latency Sensitive HPC Applications on up to 48 FPGAs Using ACCL","author":[{"full_name":"Meyer, Marius","last_name":"Meyer","first_name":"Marius"},{"first_name":"Tobias","full_name":"Kenter, Tobias","last_name":"Kenter"},{"first_name":"Lucian","last_name":"Petrica","full_name":"Petrica, Lucian"},{"full_name":"O’Brien, Kenneth","last_name":"O’Brien","first_name":"Kenneth"},{"first_name":"Michaela","last_name":"Blott","full_name":"Blott, Michaela"},{"last_name":"Plessl","full_name":"Plessl, Christian","first_name":"Christian"}],"date_created":"2024-10-14T07:51:51Z","publisher":"Springer Nature Switzerland","oa":"1","date_updated":"2024-10-14T07:55:50Z","status":"public","abstract":[{"text":"AbstractMost FPGA boards in the HPC domain are well-suited for parallel scaling because of the direct integration of versatile and high-throughput network ports. However, the utilization of their network capabilities is often challenging and error-prone because the whole network stack and communication patterns have to be implemented and managed on the FPGAs. Also, this approach conceptually involves a trade-off between the performance potential of improved communication and the impact of resource consumption for communication infrastructure, since the utilized resources on the FPGAs could otherwise be used for computations. In this work, we investigate this trade-off, firstly, by using synthetic benchmarks to evaluate the different configuration options of the communication framework ACCL and their impact on communication latency and throughput. Finally, we use our findings to implement a shallow water simulation whose scalability heavily depends on low-latency communication. With a suitable configuration of ACCL, good scaling behavior can be shown to all 48 FPGAs installed in the system. Overall, the results show that the availability of inter-FPGA communication frameworks as well as the configurability of framework and network stack are crucial to achieve the best application performance with low latency communication.","lang":"eng"}],"type":"book_chapter","publication":"Lecture Notes in Computer Science","language":[{"iso":"eng"}],"user_id":"3145","department":[{"_id":"27"},{"_id":"518"}],"_id":"56606"},{"status":"public","type":"conference","publication":"2024 34th International Conference on Field-Programmable Logic and Applications (FPL)","language":[{"iso":"eng"}],"project":[{"name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"}],"_id":"56605","user_id":"3145","department":[{"_id":"27"},{"_id":"518"}],"year":"2024","citation":{"bibtex":"@inproceedings{Opdenhövel_Alt_Plessl_Kenter_2024, title={StencilStream: A SYCL-based Stencil Simulation Framework Targeting FPGAs}, DOI={10.1109/fpl64840.2024.00023}, booktitle={2024 34th International Conference on Field-Programmable Logic and Applications (FPL)}, publisher={IEEE}, author={Opdenhövel, Jan-Oliver and Alt, Christoph and Plessl, Christian and Kenter, Tobias}, year={2024} }","mla":"Opdenhövel, Jan-Oliver, et al. “StencilStream: A SYCL-Based Stencil Simulation Framework Targeting FPGAs.” 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), IEEE, 2024, doi:10.1109/fpl64840.2024.00023.","short":"J.-O. Opdenhövel, C. Alt, C. Plessl, T. Kenter, in: 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), IEEE, 2024.","apa":"Opdenhövel, J.-O., Alt, C., Plessl, C., & Kenter, T. (2024). StencilStream: A SYCL-based Stencil Simulation Framework Targeting FPGAs. 2024 34th International Conference on Field-Programmable Logic and Applications (FPL). https://doi.org/10.1109/fpl64840.2024.00023","ama":"Opdenhövel J-O, Alt C, Plessl C, Kenter T. StencilStream: A SYCL-based Stencil Simulation Framework Targeting FPGAs. In: 2024 34th International Conference on Field-Programmable Logic and Applications (FPL). IEEE; 2024. doi:10.1109/fpl64840.2024.00023","chicago":"Opdenhövel, Jan-Oliver, Christoph Alt, Christian Plessl, and Tobias Kenter. “StencilStream: A SYCL-Based Stencil Simulation Framework Targeting FPGAs.” In 2024 34th International Conference on Field-Programmable Logic and Applications (FPL). IEEE, 2024. https://doi.org/10.1109/fpl64840.2024.00023.","ieee":"J.-O. Opdenhövel, C. Alt, C. Plessl, and T. Kenter, “StencilStream: A SYCL-based Stencil Simulation Framework Targeting FPGAs,” 2024, doi: 10.1109/fpl64840.2024.00023."},"publication_status":"published","quality_controlled":"1","title":"StencilStream: A SYCL-based Stencil Simulation Framework Targeting FPGAs","doi":"10.1109/fpl64840.2024.00023","date_updated":"2024-10-14T07:56:26Z","publisher":"IEEE","author":[{"first_name":"Jan-Oliver","last_name":"Opdenhövel","orcid":"0000-0003-2314-2784","full_name":"Opdenhövel, Jan-Oliver","id":"73960"},{"last_name":"Alt","id":"100625","full_name":"Alt, Christoph","first_name":"Christoph"},{"first_name":"Christian","last_name":"Plessl","orcid":"0000-0001-5728-9982","id":"16153","full_name":"Plessl, Christian"},{"first_name":"Tobias","last_name":"Kenter","full_name":"Kenter, Tobias","id":"3145"}],"date_created":"2024-10-14T07:49:24Z"},{"status":"public","type":"conference","publication":"2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM)","language":[{"iso":"eng"}],"user_id":"3145","department":[{"_id":"27"},{"_id":"518"}],"_id":"56607","citation":{"ama":"Tareen AR, Meyer M, Plessl C, Kenter T. HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory. In: 2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM). Vol 35. IEEE; 2024. doi:10.1109/fccm60383.2024.00014","ieee":"A. R. Tareen, M. Meyer, C. Plessl, and T. Kenter, “HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory,” in 2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM), 2024, vol. 35, doi: 10.1109/fccm60383.2024.00014.","chicago":"Tareen, Abdul Rehman, Marius Meyer, Christian Plessl, and Tobias Kenter. “HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory.” In 2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM), Vol. 35. IEEE, 2024. https://doi.org/10.1109/fccm60383.2024.00014.","mla":"Tareen, Abdul Rehman, et al. “HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory.” 2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM), vol. 35, IEEE, 2024, doi:10.1109/fccm60383.2024.00014.","bibtex":"@inproceedings{Tareen_Meyer_Plessl_Kenter_2024, title={HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory}, volume={35}, DOI={10.1109/fccm60383.2024.00014}, booktitle={2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM)}, publisher={IEEE}, author={Tareen, Abdul Rehman and Meyer, Marius and Plessl, Christian and Kenter, Tobias}, year={2024} }","short":"A.R. Tareen, M. Meyer, C. Plessl, T. Kenter, in: 2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM), IEEE, 2024.","apa":"Tareen, A. R., Meyer, M., Plessl, C., & Kenter, T. (2024). HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory. 2024 IEEE 32nd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM), 35. https://doi.org/10.1109/fccm60383.2024.00014"},"intvolume":" 35","year":"2024","publication_status":"published","quality_controlled":"1","doi":"10.1109/fccm60383.2024.00014","title":"HiHiSpMV: Sparse Matrix Vector Multiplication with Hierarchical Row Reductions on FPGAs with High Bandwidth Memory","author":[{"first_name":"Abdul Rehman","id":"76938","full_name":"Tareen, Abdul Rehman","last_name":"Tareen"},{"first_name":"Marius","last_name":"Meyer","full_name":"Meyer, Marius","id":"40778"},{"orcid":"0000-0001-5728-9982","last_name":"Plessl","full_name":"Plessl, Christian","id":"16153","first_name":"Christian"},{"last_name":"Kenter","full_name":"Kenter, Tobias","id":"3145","first_name":"Tobias"}],"date_created":"2024-10-14T07:59:08Z","volume":35,"publisher":"IEEE","date_updated":"2024-10-14T12:27:55Z"},{"publication":"2024 34th International Conference on Field-Programmable Logic and Applications (FPL)","type":"conference","abstract":[{"lang":"eng","text":"The computation of electron repulsion integrals (ERIs) is a key component for quantum chemical methods. The intensive computation and bandwidth demand for ERI evaluation presents a significant challenge for quantum-mechanics-based atomistic simulations with hybrid density functional theory: due to the tens of trillions of ERI computations in each time step, practical applications are usually limited to thousands of atoms. In this work, we propose SERI, a high-throughput streaming accelerator for ERI computation on HBM-based FPGAs. In contrast to prior buffer-based designs, SERI proposes a novel streaming architecture to address the on-chip buffer limitation and the floorplanning challenge, and leverages the high-bandwidth memory to overcome the bandwidth bottleneck in prior designs. Moreover, to meet the varying computation, bandwidth, and floorplanning requirements between the 55 canonical quartet classes in ERI calculation, we design an automation tool, together with an accurate performance model, to automatically customize the architecture and floorplanning strategy for each canonical quartet class to maximize their throughput. Our performance evaluation on the AMD/Xilinx Alveo U280 FPGA board shows that, SERI achieves an average speedup of 9.80 x over the previous best-performing FPGA design, a 3.21x speedup over a 64-core AMD EPYC 7713 CPU, and a 15.64x speedup over an Nvidia A40 GPU. It reaches a peak throughput of 23.8 GERIS ($10^9$ ERIs per second) on one Alveo U280 FPGA. SERI will be released soon at https://github.com/SFU-HiAccel/SERI."}],"status":"public","_id":"56609","project":[{"name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"}],"department":[{"_id":"27"},{"_id":"518"}],"user_id":"77439","language":[{"iso":"eng"}],"quality_controlled":"1","publication_status":"published","year":"2024","page":"60-68","citation":{"apa":"Stachura, P., Li, G., Wu, X., Plessl, C., & Fang, Z. (2024). SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry using HBM-based FPGAs. 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), 60–68. https://doi.org/10.1109/fpl64840.2024.00018","bibtex":"@inproceedings{Stachura_Li_Wu_Plessl_Fang_2024, title={SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry using HBM-based FPGAs}, DOI={10.1109/fpl64840.2024.00018}, booktitle={2024 34th International Conference on Field-Programmable Logic and Applications (FPL)}, publisher={IEEE}, author={Stachura, Philip and Li, Guanyu and Wu, Xin and Plessl, Christian and Fang, Zhenman}, year={2024}, pages={60–68} }","short":"P. Stachura, G. Li, X. Wu, C. Plessl, Z. Fang, in: 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), IEEE, 2024, pp. 60–68.","mla":"Stachura, Philip, et al. “SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry Using HBM-Based FPGAs.” 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), IEEE, 2024, pp. 60–68, doi:10.1109/fpl64840.2024.00018.","ieee":"P. Stachura, G. Li, X. Wu, C. Plessl, and Z. Fang, “SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry using HBM-based FPGAs,” in 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), 2024, pp. 60–68, doi: 10.1109/fpl64840.2024.00018.","chicago":"Stachura, Philip, Guanyu Li, Xin Wu, Christian Plessl, and Zhenman Fang. “SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry Using HBM-Based FPGAs.” In 2024 34th International Conference on Field-Programmable Logic and Applications (FPL), 60–68. IEEE, 2024. https://doi.org/10.1109/fpl64840.2024.00018.","ama":"Stachura P, Li G, Wu X, Plessl C, Fang Z. SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry using HBM-based FPGAs. In: 2024 34th International Conference on Field-Programmable Logic and Applications (FPL). IEEE; 2024:60-68. doi:10.1109/fpl64840.2024.00018"},"publisher":"IEEE","date_updated":"2024-10-15T08:37:27Z","date_created":"2024-10-14T08:44:44Z","author":[{"first_name":"Philip","last_name":"Stachura","full_name":"Stachura, Philip"},{"full_name":"Li, Guanyu","last_name":"Li","first_name":"Guanyu"},{"id":"77439","full_name":"Wu, Xin","last_name":"Wu","first_name":"Xin"},{"orcid":"0000-0001-5728-9982","last_name":"Plessl","id":"16153","full_name":"Plessl, Christian","first_name":"Christian"},{"first_name":"Zhenman","last_name":"Fang","full_name":"Fang, Zhenman"}],"title":"SERI: High-Throughput Streaming Acceleration of Electron Repulsion Integral Computation in Quantum Chemistry using HBM-based FPGAs","doi":"10.1109/fpl64840.2024.00018","main_file_link":[{"url":"https://ieeexplore.ieee.org/document/10705609"}]},{"quality_controlled":"1","publication_status":"published","citation":{"short":"M. Büttner, C. Alt, T. Kenter, H. Köstler, C. Plessl, V. Aizinger, in: Proceedings of the Platform for Advanced Scientific Computing Conference (PASC), ACM, 2024.","bibtex":"@inproceedings{Büttner_Alt_Kenter_Köstler_Plessl_Aizinger_2024, title={Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL}, DOI={10.1145/3659914.3659925}, number={11}, booktitle={Proceedings of the Platform for Advanced Scientific Computing Conference (PASC)}, publisher={ACM}, author={Büttner, Markus and Alt, Christoph and Kenter, Tobias and Köstler, Harald and Plessl, Christian and Aizinger, Vadym}, year={2024} }","mla":"Büttner, Markus, et al. “Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL.” Proceedings of the Platform for Advanced Scientific Computing Conference (PASC), 11, ACM, 2024, doi:10.1145/3659914.3659925.","apa":"Büttner, M., Alt, C., Kenter, T., Köstler, H., Plessl, C., & Aizinger, V. (2024). Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL. Proceedings of the Platform for Advanced Scientific Computing Conference (PASC), Article 11. https://doi.org/10.1145/3659914.3659925","ieee":"M. Büttner, C. Alt, T. Kenter, H. Köstler, C. Plessl, and V. Aizinger, “Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL,” 2024, doi: 10.1145/3659914.3659925.","chicago":"Büttner, Markus, Christoph Alt, Tobias Kenter, Harald Köstler, Christian Plessl, and Vadym Aizinger. “Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL.” In Proceedings of the Platform for Advanced Scientific Computing Conference (PASC). ACM, 2024. https://doi.org/10.1145/3659914.3659925.","ama":"Büttner M, Alt C, Kenter T, Köstler H, Plessl C, Aizinger V. Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL. In: Proceedings of the Platform for Advanced Scientific Computing Conference (PASC). ACM; 2024. doi:10.1145/3659914.3659925"},"year":"2024","date_created":"2024-05-16T13:24:49Z","author":[{"full_name":"Büttner, Markus","last_name":"Büttner","first_name":"Markus"},{"first_name":"Christoph","last_name":"Alt","full_name":"Alt, Christoph","id":"100625"},{"full_name":"Kenter, Tobias","id":"3145","last_name":"Kenter","first_name":"Tobias"},{"last_name":"Köstler","full_name":"Köstler, Harald","first_name":"Harald"},{"last_name":"Plessl","orcid":"0000-0001-5728-9982","id":"16153","full_name":"Plessl, Christian","first_name":"Christian"},{"first_name":"Vadym","full_name":"Aizinger, Vadym","last_name":"Aizinger"}],"date_updated":"2024-11-27T22:50:19Z","publisher":"ACM","doi":"10.1145/3659914.3659925","title":"Enabling Performance Portability for Shallow Water Equations on CPUs, GPUs, and FPGAs with SYCL","publication":"Proceedings of the Platform for Advanced Scientific Computing Conference (PASC)","type":"conference","status":"public","department":[{"_id":"27"},{"_id":"518"}],"user_id":"16153","_id":"54312","project":[{"name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"}],"language":[{"iso":"eng"}],"article_number":"11"},{"article_number":"123016","language":[{"iso":"eng"}],"_id":"57839","project":[{"_id":"52","name":"PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing"}],"department":[{"_id":"15"},{"_id":"170"},{"_id":"293"},{"_id":"35"},{"_id":"230"},{"_id":"27"}],"user_id":"16199","abstract":[{"text":"Abstract\r\n Experiments with ultracold atoms in optical lattices usually involve a weak parabolic trapping potential which merely serves to confine the atoms, but otherwise remains negligible. In contrast, we suggest a different class of experiments in which the presence of a stronger trap is an essential part of the set-up. Because the trap-modified on-site energies exhibit a slowly varying level spacing, similar to that of an anharmonic oscillator, an additional time-periodic trap modulation with judiciously chosen parameters creates nonlinear resonances which enable efficient Floquet engineering. We employ a Mathieu approximation for constructing the near-resonant Floquet states in an accurate manner and demonstrate the emergence of effective ground states from the resonant trap eigenstates. Moreover, we show that the population of the Floquet states is strongly affected by the phase of a sudden turn-on of the trap modulation, which leads to significantly modified and rich dynamics. As a guideline for further studies, we argue that the deliberate population of only the resonance-induced effective ground states will allow one to realize Floquet condensates which follow classical periodic orbits, thus providing challenging future perspectives for the investigation of the quantum–classical correspondence.","lang":"eng"}],"status":"public","publication":"New Journal of Physics","type":"journal_article","title":"Floquet dynamics of ultracold atoms in optical lattices with a parametrically modulated trapping potential","doi":"10.1088/1367-2630/ad9b47","date_updated":"2024-12-18T14:00:41Z","publisher":"IOP Publishing","volume":26,"author":[{"last_name":"Ali","full_name":"Ali, Usman","first_name":"Usman"},{"first_name":"Martin","full_name":"Holthaus, Martin","last_name":"Holthaus"},{"last_name":"Meier","orcid":"0000-0001-8864-2072","full_name":"Meier, Torsten","id":"344","first_name":"Torsten"}],"date_created":"2024-12-18T13:59:34Z","year":"2024","intvolume":" 26","citation":{"chicago":"Ali, Usman, Martin Holthaus, and Torsten Meier. “Floquet Dynamics of Ultracold Atoms in Optical Lattices with a Parametrically Modulated Trapping Potential.” New Journal of Physics 26, no. 12 (2024). https://doi.org/10.1088/1367-2630/ad9b47.","ieee":"U. Ali, M. Holthaus, and T. Meier, “Floquet dynamics of ultracold atoms in optical lattices with a parametrically modulated trapping potential,” New Journal of Physics, vol. 26, no. 12, Art. no. 123016, 2024, doi: 10.1088/1367-2630/ad9b47.","ama":"Ali U, Holthaus M, Meier T. Floquet dynamics of ultracold atoms in optical lattices with a parametrically modulated trapping potential. New Journal of Physics. 2024;26(12). doi:10.1088/1367-2630/ad9b47","apa":"Ali, U., Holthaus, M., & Meier, T. (2024). Floquet dynamics of ultracold atoms in optical lattices with a parametrically modulated trapping potential. New Journal of Physics, 26(12), Article 123016. https://doi.org/10.1088/1367-2630/ad9b47","bibtex":"@article{Ali_Holthaus_Meier_2024, title={Floquet dynamics of ultracold atoms in optical lattices with a parametrically modulated trapping potential}, volume={26}, DOI={10.1088/1367-2630/ad9b47}, number={12123016}, journal={New Journal of Physics}, publisher={IOP Publishing}, author={Ali, Usman and Holthaus, Martin and Meier, Torsten}, year={2024} }","short":"U. Ali, M. Holthaus, T. Meier, New Journal of Physics 26 (2024).","mla":"Ali, Usman, et al. “Floquet Dynamics of Ultracold Atoms in Optical Lattices with a Parametrically Modulated Trapping Potential.” New Journal of Physics, vol. 26, no. 12, 123016, IOP Publishing, 2024, doi:10.1088/1367-2630/ad9b47."},"publication_identifier":{"issn":["1367-2630"]},"publication_status":"published","issue":"12"},{"intvolume":" 1","citation":{"ieee":"D. Bauch, N. Köcher, N. Heinisch, and S. Schumacher, “Time-bin entanglement in the deterministic generation of linear photonic cluster states,” APL Quantum, vol. 1, no. 3, Art. no. 036110, 2024, doi: 10.1063/5.0214197.","chicago":"Bauch, David, Nikolas Köcher, Nils Heinisch, and Stefan Schumacher. “Time-Bin Entanglement in the Deterministic Generation of Linear Photonic Cluster States.” APL Quantum 1, no. 3 (2024). https://doi.org/10.1063/5.0214197.","ama":"Bauch D, Köcher N, Heinisch N, Schumacher S. Time-bin entanglement in the deterministic generation of linear photonic cluster states. APL Quantum. 2024;1(3). doi:10.1063/5.0214197","mla":"Bauch, David, et al. “Time-Bin Entanglement in the Deterministic Generation of Linear Photonic Cluster States.” APL Quantum, vol. 1, no. 3, 036110, AIP Publishing, 2024, doi:10.1063/5.0214197.","bibtex":"@article{Bauch_Köcher_Heinisch_Schumacher_2024, title={Time-bin entanglement in the deterministic generation of linear photonic cluster states}, volume={1}, DOI={10.1063/5.0214197}, number={3036110}, journal={APL Quantum}, publisher={AIP Publishing}, author={Bauch, David and Köcher, Nikolas and Heinisch, Nils and Schumacher, Stefan}, year={2024} }","short":"D. Bauch, N. Köcher, N. Heinisch, S. Schumacher, APL Quantum 1 (2024).","apa":"Bauch, D., Köcher, N., Heinisch, N., & Schumacher, S. (2024). Time-bin entanglement in the deterministic generation of linear photonic cluster states. APL Quantum, 1(3), Article 036110. https://doi.org/10.1063/5.0214197"},"publication_identifier":{"issn":["2835-0103"]},"publication_status":"published","doi":"10.1063/5.0214197","volume":1,"author":[{"first_name":"David","last_name":"Bauch","full_name":"Bauch, David"},{"first_name":"Nikolas","last_name":"Köcher","id":"79191","full_name":"Köcher, Nikolas"},{"first_name":"Nils","id":"90283","full_name":"Heinisch, Nils","last_name":"Heinisch","orcid":"0009-0006-0984-2097"},{"orcid":"0000-0003-4042-4951","last_name":"Schumacher","full_name":"Schumacher, Stefan","id":"27271","first_name":"Stefan"}],"date_updated":"2025-09-12T11:11:32Z","status":"public","type":"journal_article","article_number":"036110","department":[{"_id":"15"},{"_id":"170"},{"_id":"297"},{"_id":"35"},{"_id":"230"},{"_id":"27"},{"_id":"429"},{"_id":"623"}],"user_id":"16199","_id":"61251","project":[{"name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen","_id":"53"},{"_id":"56","name":"TRR 142 - Project Area C"},{"name":"TRR 142; TP C09: Ideale Erzeugung von Photonenpaaren für Verschränkungsaustausch bei Telekom Wellenlängen","_id":"173"},{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"},{"_id":"266","name":"PhoQC: Photonisches Quantencomputing"}],"year":"2024","issue":"3","title":"Time-bin entanglement in the deterministic generation of linear photonic cluster states","date_created":"2025-09-12T11:08:59Z","publisher":"AIP Publishing","abstract":[{"lang":"eng","text":"We theoretically investigate strategies for the deterministic creation of trains of time-bin entangled photons using an individual quantum emitter described by a Λ-type electronic system. We explicitly demonstrate the theoretical generation of linear cluster states with substantial numbers of entangled photonic qubits in full microscopic numerical simulations. The underlying scheme is based on the manipulation of ground state coherences through precise optical driving. One important finding is that the most easily accessible quality metrics, the achievable rotation fidelities, fall short in assessing the actual quantum correlations of the emitted photons in the face of losses. To address this, we explicitly calculate stabilizer generator expectation values as a superior gauge for the quantum properties of the generated many-photon state. With widespread applicability in other emitter and excitation–emission schemes also, our work lays the conceptual foundations for an in-depth practical analysis of time-bin entanglement based on full numerical simulations with predictive capabilities for realistic systems and setups, including losses and imperfections. The specific results shown in the present work illustrate that with controlled minimization of losses and realistic system parameters for quantum-dot type systems, useful linear cluster states of significant lengths can be generated in the calculations, discussing the possibility of scalability for quantum information processing endeavors."}],"publication":"APL Quantum","language":[{"iso":"eng"}]},{"volume":6,"author":[{"id":"90283","full_name":"Heinisch, Nils","last_name":"Heinisch","orcid":"0009-0006-0984-2097","first_name":"Nils"},{"id":"79191","full_name":"Köcher, Nikolas","last_name":"Köcher","first_name":"Nikolas"},{"first_name":"David","full_name":"Bauch, David","last_name":"Bauch"},{"full_name":"Schumacher, Stefan","id":"27271","last_name":"Schumacher","orcid":"0000-0003-4042-4951","first_name":"Stefan"}],"date_created":"2025-09-12T11:16:31Z","date_updated":"2025-09-12T11:18:05Z","publisher":"American Physical Society (APS)","doi":"10.1103/physrevresearch.6.l012017","title":"Swing-up dynamics in quantum emitter cavity systems: Near ideal single photons and entangled photon pairs","issue":"1","publication_identifier":{"issn":["2643-1564"]},"publication_status":"published","intvolume":" 6","citation":{"short":"N. Heinisch, N. Köcher, D. Bauch, S. Schumacher, Physical Review Research 6 (2024).","mla":"Heinisch, Nils, et al. “Swing-up Dynamics in Quantum Emitter Cavity Systems: Near Ideal Single Photons and Entangled Photon Pairs.” Physical Review Research, vol. 6, no. 1, L012017, American Physical Society (APS), 2024, doi:10.1103/physrevresearch.6.l012017.","bibtex":"@article{Heinisch_Köcher_Bauch_Schumacher_2024, title={Swing-up dynamics in quantum emitter cavity systems: Near ideal single photons and entangled photon pairs}, volume={6}, DOI={10.1103/physrevresearch.6.l012017}, number={1L012017}, journal={Physical Review Research}, publisher={American Physical Society (APS)}, author={Heinisch, Nils and Köcher, Nikolas and Bauch, David and Schumacher, Stefan}, year={2024} }","apa":"Heinisch, N., Köcher, N., Bauch, D., & Schumacher, S. (2024). Swing-up dynamics in quantum emitter cavity systems: Near ideal single photons and entangled photon pairs. Physical Review Research, 6(1), Article L012017. https://doi.org/10.1103/physrevresearch.6.l012017","chicago":"Heinisch, Nils, Nikolas Köcher, David Bauch, and Stefan Schumacher. “Swing-up Dynamics in Quantum Emitter Cavity Systems: Near Ideal Single Photons and Entangled Photon Pairs.” Physical Review Research 6, no. 1 (2024). https://doi.org/10.1103/physrevresearch.6.l012017.","ieee":"N. Heinisch, N. Köcher, D. Bauch, and S. Schumacher, “Swing-up dynamics in quantum emitter cavity systems: Near ideal single photons and entangled photon pairs,” Physical Review Research, vol. 6, no. 1, Art. no. L012017, 2024, doi: 10.1103/physrevresearch.6.l012017.","ama":"Heinisch N, Köcher N, Bauch D, Schumacher S. Swing-up dynamics in quantum emitter cavity systems: Near ideal single photons and entangled photon pairs. Physical Review Research. 2024;6(1). doi:10.1103/physrevresearch.6.l012017"},"year":"2024","department":[{"_id":"15"},{"_id":"170"},{"_id":"297"},{"_id":"35"},{"_id":"230"},{"_id":"429"},{"_id":"27"}],"user_id":"16199","_id":"61253","project":[{"name":"Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"},{"name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen","_id":"53"},{"_id":"56","name":"TRR 142 - Project Area C"},{"_id":"173","name":"TRR 142; TP C09: Ideale Erzeugung von Photonenpaaren für Verschränkungsaustausch bei Telekom Wellenlängen"}],"language":[{"iso":"eng"}],"article_number":"L012017","publication":"Physical Review Research","type":"journal_article","status":"public","abstract":[{"lang":"eng","text":"In the SUPER scheme (Swing-UP of the quantum EmitteR population), excitation of a quantum emitter is achieved with two off-resonant, red-detuned laser pulses. This allows the generation of high-quality single photons without the need of complex laser stray light suppression or careful spectral filtering. In the present work, we extend this promising method to quantum emitters, specifically semiconductor quantum dots, inside a resonant optical cavity. A significant advantage of the SUPER scheme is identified in that it eliminates re-excitation of the quantum emitter by suppressing photon emission during the excitation cycle. This, in turn, leads to almost ideal single-photon purity, overcoming a major factor typically limiting the quality of photons generated with quantum emitters in high-quality cavities. We further find that for cavity-mediated biexciton emission of degenerate photon pairs, the SUPER scheme leads to near-perfect biexciton initialization with very high values of polarization entanglement of emitted photon pairs.\r\n \r\n \r\n \r\n \r\n Published by the American Physical Society\r\n 2024\r\n \r\n \r\n "}]},{"publisher":"Walter de Gruyter GmbH","date_updated":"2025-09-12T11:22:41Z","volume":13,"author":[{"last_name":"Schneider","full_name":"Schneider, Tobias","first_name":"Tobias"},{"first_name":"Wenlong","full_name":"Gao, Wenlong","id":"78853","last_name":"Gao"},{"first_name":"Thomas","orcid":"0000-0002-8662-1101","last_name":"Zentgraf","full_name":"Zentgraf, Thomas","id":"30525"},{"full_name":"Schumacher, Stefan","id":"27271","last_name":"Schumacher","orcid":"0000-0003-4042-4951","first_name":"Stefan"},{"first_name":"Xuekai","full_name":"Ma, Xuekai","id":"59416","last_name":"Ma"}],"date_created":"2025-09-12T11:19:22Z","title":"Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates","doi":"10.1515/nanoph-2023-0556","publication_identifier":{"issn":["2192-8614"]},"publication_status":"published","issue":"4","year":"2024","page":"509-518","intvolume":" 13","citation":{"ieee":"T. Schneider, W. Gao, T. Zentgraf, S. Schumacher, and X. Ma, “Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates,” Nanophotonics, vol. 13, no. 4, pp. 509–518, 2024, doi: 10.1515/nanoph-2023-0556.","chicago":"Schneider, Tobias, Wenlong Gao, Thomas Zentgraf, Stefan Schumacher, and Xuekai Ma. “Topological Edge and Corner States in Coupled Wave Lattices in Nonlinear Polariton Condensates.” Nanophotonics 13, no. 4 (2024): 509–18. https://doi.org/10.1515/nanoph-2023-0556.","ama":"Schneider T, Gao W, Zentgraf T, Schumacher S, Ma X. Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates. Nanophotonics. 2024;13(4):509-518. doi:10.1515/nanoph-2023-0556","apa":"Schneider, T., Gao, W., Zentgraf, T., Schumacher, S., & Ma, X. (2024). Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates. Nanophotonics, 13(4), 509–518. https://doi.org/10.1515/nanoph-2023-0556","mla":"Schneider, Tobias, et al. “Topological Edge and Corner States in Coupled Wave Lattices in Nonlinear Polariton Condensates.” Nanophotonics, vol. 13, no. 4, Walter de Gruyter GmbH, 2024, pp. 509–18, doi:10.1515/nanoph-2023-0556.","short":"T. Schneider, W. Gao, T. Zentgraf, S. Schumacher, X. Ma, Nanophotonics 13 (2024) 509–518.","bibtex":"@article{Schneider_Gao_Zentgraf_Schumacher_Ma_2024, title={Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates}, volume={13}, DOI={10.1515/nanoph-2023-0556}, number={4}, journal={Nanophotonics}, publisher={Walter de Gruyter GmbH}, author={Schneider, Tobias and Gao, Wenlong and Zentgraf, Thomas and Schumacher, Stefan and Ma, Xuekai}, year={2024}, pages={509–518} }"},"_id":"61255","project":[{"_id":"52","name":"Computing Resources Provided by the Paderborn Center for Parallel Computing"},{"name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen","_id":"53"},{"name":"TRR 142 - Project Area A","_id":"54"},{"_id":"55","name":"TRR 142 - Project Area B"},{"_id":"61","name":"TRR 142; TP A04: Nichtlineare Quantenprozesstomographie und Photonik mit Polaritonen in Mikrokavitäten"},{"name":"TRR 142; TP B09: Effiziente Erzeugung mit maßgeschneiderter optischer Phaselage der zweiten Harmonischen mittels Quasi-gebundener Zustände in GaAs Metaoberflächen","_id":"170"}],"department":[{"_id":"15"},{"_id":"170"},{"_id":"297"},{"_id":"705"},{"_id":"35"},{"_id":"230"},{"_id":"429"},{"_id":"27"}],"user_id":"16199","language":[{"iso":"eng"}],"publication":"Nanophotonics","type":"journal_article","abstract":[{"lang":"eng","text":"Abstract\r\n Topological states have been widely investigated in different types of systems and lattices. In the present work, we report on topological edge states in double-wave (DW) chains, which can be described by a generalized Aubry-André-Harper (AAH) model. For the specific system of a driven-dissipative exciton polariton system we show that in such potential chains, different types of edge states can form. For resonant optical excitation, we further find that the optical nonlinearity leads to a multistability of different edge states. This includes topologically protected edge states evolved directly from individual linear eigenstates as well as additional edge states that originate from nonlinearity-induced localization of bulk states. Extending the system into two dimensions (2D) by stacking horizontal DW chains in the vertical direction, we also create 2D multi-wave lattices. In such 2D lattices multiple Su–Schrieffer–Heeger (SSH) chains appear along the vertical direction. The combination of DW chains in the horizonal and SSH chains in the vertical direction then results in the formation of higher-order topological insulator corner states. Multistable corner states emerge in the nonlinear regime."}],"status":"public"},{"_id":"61257","project":[{"name":"Computing Resources Provided by the Paderborn Center for Parallel Computing","_id":"52"},{"_id":"53","name":"TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten zu funktionellen Strukturen"},{"name":"TRR 142 - Project Area A","_id":"54"},{"_id":"61","name":"TRR 142; TP A04: Nichtlineare Quantenprozesstomographie und Photonik mit Polaritonen in Mikrokavitäten"}],"department":[{"_id":"15"},{"_id":"170"},{"_id":"297"},{"_id":"705"},{"_id":"35"},{"_id":"230"},{"_id":"27"},{"_id":"429"}],"user_id":"16199","article_number":"013148","language":[{"iso":"eng"}],"publication":"Physical Review Research","type":"journal_article","abstract":[{"text":"Exceptional points (EPs), with their intriguing spectral topology, have attracted considerable attention in a broad range of physical systems, with potential sensing applications driving much of the present research in this field. Here, we investigate spectral topology and EPs in systems with significant nonlinearity, exemplified by a nonequilibrium exciton-polariton condensate. With the possibility to control loss and gain and nonlinearity by optical means, this system allows for a comprehensive analysis of the interplay of nonlinearities (Kerr type and saturable gain) and non-Hermiticity. Not only do we find that EPs can be intentionally shifted in parameter space by the saturable gain, but we also observe intriguing rotations and intersections of Riemann surfaces and find nonlinearity-enhanced sensing capabilities. With this, our results illustrate the potential of tailoring spectral topology and related phenomena in non-Hermitian systems by nonlinearity.\r\n \r\n \r\n \r\n \r\n Published by the American Physical Society\r\n 2024\r\n \r\n \r\n ","lang":"eng"}],"status":"public","date_updated":"2025-09-12T11:24:59Z","publisher":"American Physical Society (APS)","volume":6,"author":[{"first_name":"Jan","last_name":"Wingenbach","full_name":"Wingenbach, Jan","id":"69187"},{"first_name":"Stefan","last_name":"Schumacher","orcid":"0000-0003-4042-4951","full_name":"Schumacher, Stefan","id":"27271"},{"first_name":"Xuekai","last_name":"Ma","id":"59416","full_name":"Ma, Xuekai"}],"date_created":"2025-09-12T11:23:33Z","title":"Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems","doi":"10.1103/physrevresearch.6.013148","publication_identifier":{"issn":["2643-1564"]},"publication_status":"published","issue":"1","year":"2024","intvolume":" 6","citation":{"ama":"Wingenbach J, Schumacher S, Ma X. Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems. Physical Review Research. 2024;6(1). doi:10.1103/physrevresearch.6.013148","chicago":"Wingenbach, Jan, Stefan Schumacher, and Xuekai Ma. “Manipulating Spectral Topology and Exceptional Points by Nonlinearity in Non-Hermitian Polariton Systems.” Physical Review Research 6, no. 1 (2024). https://doi.org/10.1103/physrevresearch.6.013148.","ieee":"J. Wingenbach, S. Schumacher, and X. Ma, “Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems,” Physical Review Research, vol. 6, no. 1, Art. no. 013148, 2024, doi: 10.1103/physrevresearch.6.013148.","mla":"Wingenbach, Jan, et al. “Manipulating Spectral Topology and Exceptional Points by Nonlinearity in Non-Hermitian Polariton Systems.” Physical Review Research, vol. 6, no. 1, 013148, American Physical Society (APS), 2024, doi:10.1103/physrevresearch.6.013148.","short":"J. Wingenbach, S. Schumacher, X. Ma, Physical Review Research 6 (2024).","bibtex":"@article{Wingenbach_Schumacher_Ma_2024, title={Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems}, volume={6}, DOI={10.1103/physrevresearch.6.013148}, number={1013148}, journal={Physical Review Research}, publisher={American Physical Society (APS)}, author={Wingenbach, Jan and Schumacher, Stefan and Ma, Xuekai}, year={2024} }","apa":"Wingenbach, J., Schumacher, S., & Ma, X. (2024). Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems. Physical Review Research, 6(1), Article 013148. https://doi.org/10.1103/physrevresearch.6.013148"}}]