--- _id: '65316' abstract: - lang: eng text: Metasurfaces are powerful tools for manipulating light using small structures on the nanoscale. In most metasurfaces, near-field couplings are treated as being unfavorable perturbations. Here, we experimentally investigate a structure consisting of sinusoidally modulated silicon waveguides where near-field coupling of local resonances leads to negative coupling, i.e., a negative coupling constant. This gives rise to wave-vector-dependent eigenstates of elliptical, linear, and circular polarizations. In particular, fully circular polarization states are not only present at a single point in momentum space (k-space) but also along a line. This circular polarization line, as well as a linear polarization line, emanates from a polarization degeneracy at the Dirac point. We experimentally validate the existence of these eigenstates and demonstrate the energy-, polarization-, and wave vector dependence of this metasurface as well as its sensitivity to fabrication tolerances. By tuning the incident k-vector, certain polarization-energy eigenstates are strongly reflected, allowing for uses in angle-tunable polarization filters and light sources. author: - first_name: Helene full_name: Wetter, Helene last_name: Wetter - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: Falk full_name: Rehberg, Falk last_name: Rehberg - first_name: Wenlong full_name: Gao, Wenlong last_name: Gao - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 citation: ama: Wetter H, Wingenbach J, Rehberg F, Gao W, Schumacher S, Zentgraf T. Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling. ACS Photonics. 2026;13:2128-2133. doi:10.1021/acsphotonics.5c02865 apa: Wetter, H., Wingenbach, J., Rehberg, F., Gao, W., Schumacher, S., & Zentgraf, T. (2026). Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling. ACS Photonics, 13, 2128–2133. https://doi.org/10.1021/acsphotonics.5c02865 bibtex: '@article{Wetter_Wingenbach_Rehberg_Gao_Schumacher_Zentgraf_2026, title={Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling}, volume={13}, DOI={10.1021/acsphotonics.5c02865}, journal={ACS Photonics}, publisher={American Chemical Society (ACS)}, author={Wetter, Helene and Wingenbach, Jan and Rehberg, Falk and Gao, Wenlong and Schumacher, Stefan and Zentgraf, Thomas}, year={2026}, pages={2128–2133} }' chicago: 'Wetter, Helene, Jan Wingenbach, Falk Rehberg, Wenlong Gao, Stefan Schumacher, and Thomas Zentgraf. “Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling.” ACS Photonics 13 (2026): 2128–33. https://doi.org/10.1021/acsphotonics.5c02865.' ieee: 'H. Wetter, J. Wingenbach, F. Rehberg, W. Gao, S. Schumacher, and T. Zentgraf, “Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling,” ACS Photonics, vol. 13, pp. 2128–2133, 2026, doi: 10.1021/acsphotonics.5c02865.' mla: Wetter, Helene, et al. “Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling.” ACS Photonics, vol. 13, American Chemical Society (ACS), 2026, pp. 2128–33, doi:10.1021/acsphotonics.5c02865. short: H. Wetter, J. Wingenbach, F. Rehberg, W. Gao, S. Schumacher, T. Zentgraf, ACS Photonics 13 (2026) 2128–2133. date_created: 2026-04-02T07:25:30Z date_updated: 2026-04-20T05:09:57Z department: - _id: '15' - _id: '230' - _id: '289' - _id: '623' doi: 10.1021/acsphotonics.5c02865 external_id: arxiv: - '2512.14452' intvolume: ' 13' keyword: - metasurface - waveguides - Dirac point - polarization - negative coupling language: - iso: eng main_file_link: - url: https://pubs.acs.org/doi/10.1021/acsphotonics.5c02865 page: 2128-2133 publication: ACS Photonics publication_identifier: issn: - 2330-4022 - 2330-4022 publication_status: published publisher: American Chemical Society (ACS) quality_controlled: '1' status: public title: Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling type: journal_article user_id: '30525' volume: 13 year: '2026' ... --- _id: '60298' abstract: - lang: eng text: In this work, we introduce PHOENIX, a highly optimized explicit open-source solver for two-dimensional nonlinear Schrödinger equations with extensions. The nonlinear Schrödinger equation and its extensions (Gross-Pitaevskii equation) are widely studied to model and analyze complex phenomena in fields such as optics, condensed matter physics, fluid dynamics, and plasma physics. It serves as a powerful tool for understanding nonlinear wave dynamics, soliton formation, and the interplay between nonlinearity, dispersion, and diffraction. By extending the nonlinear Schrödinger equation, various physical effects such as non-Hermiticity, spin-orbit interaction, and quantum optical aspects can be incorporated. PHOENIX is designed to accommodate a wide range of applications by a straightforward extendability without the need for user knowledge of computing architectures or performance optimization. The high performance and power efficiency of PHOENIX are demonstrated on a wide range of entry-class to high-end consumer and high-performance computing GPUs and CPUs. Compared to a more conventional MATLAB implementation, a speedup of up to three orders of magnitude and energy savings of up to 99.8% are achieved. The performance is compared to a performance model showing that PHOENIX performs close to the relevant performance bounds in many situations. The possibilities of PHOENIX are demonstrated with a range of practical examples from the realm of nonlinear (quantum) photonics in planar microresonators with active media including exciton-polariton condensates. Examples range from solutions on very large grids, the use of local optimization algorithms, to Monte Carlo ensemble evolutions with quantum noise enabling the tomography of the system's quantum state. article_number: '109689' article_type: original author: - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: David full_name: Bauch, David id: '44172' last_name: Bauch - first_name: Xuekai full_name: Ma, Xuekai id: '59416' last_name: Ma - first_name: Robert full_name: Schade, Robert id: '75963' last_name: Schade orcid: 0000-0002-6268-5397 - first_name: Christian full_name: Plessl, Christian id: '16153' last_name: Plessl orcid: 0000-0001-5728-9982 - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 citation: ama: Wingenbach J, Bauch D, Ma X, Schade R, Plessl C, Schumacher S. PHOENIX – Paderborn highly optimized and energy efficient solver for two-dimensional nonlinear Schrödinger equations with integrated extensions. Computer Physics Communications. 2025;315. doi:10.1016/j.cpc.2025.109689 apa: Wingenbach, J., Bauch, D., Ma, X., Schade, R., Plessl, C., & Schumacher, S. (2025). PHOENIX – Paderborn highly optimized and energy efficient solver for two-dimensional nonlinear Schrödinger equations with integrated extensions. Computer Physics Communications, 315, Article 109689. https://doi.org/10.1016/j.cpc.2025.109689 bibtex: '@article{Wingenbach_Bauch_Ma_Schade_Plessl_Schumacher_2025, title={PHOENIX – Paderborn highly optimized and energy efficient solver for two-dimensional nonlinear Schrödinger equations with integrated extensions}, volume={315}, DOI={10.1016/j.cpc.2025.109689}, number={109689}, journal={Computer Physics Communications}, publisher={Elsevier BV}, author={Wingenbach, Jan and Bauch, David and Ma, Xuekai and Schade, Robert and Plessl, Christian and Schumacher, Stefan}, year={2025} }' chicago: Wingenbach, Jan, David Bauch, Xuekai Ma, Robert Schade, Christian Plessl, and Stefan Schumacher. “PHOENIX – Paderborn Highly Optimized and Energy Efficient Solver for Two-Dimensional Nonlinear Schrödinger Equations with Integrated Extensions.” Computer Physics Communications 315 (2025). https://doi.org/10.1016/j.cpc.2025.109689. ieee: 'J. Wingenbach, D. Bauch, X. Ma, R. Schade, C. Plessl, and S. Schumacher, “PHOENIX – Paderborn highly optimized and energy efficient solver for two-dimensional nonlinear Schrödinger equations with integrated extensions,” Computer Physics Communications, vol. 315, Art. no. 109689, 2025, doi: 10.1016/j.cpc.2025.109689.' mla: Wingenbach, Jan, et al. “PHOENIX – Paderborn Highly Optimized and Energy Efficient Solver for Two-Dimensional Nonlinear Schrödinger Equations with Integrated Extensions.” Computer Physics Communications, vol. 315, 109689, Elsevier BV, 2025, doi:10.1016/j.cpc.2025.109689. short: J. Wingenbach, D. Bauch, X. Ma, R. Schade, C. Plessl, S. Schumacher, Computer Physics Communications 315 (2025). date_created: 2025-06-23T07:38:52Z date_updated: 2025-06-29T12:00:36Z department: - _id: '27' doi: 10.1016/j.cpc.2025.109689 intvolume: ' 315' language: - iso: eng project: - _id: '52' name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing' publication: Computer Physics Communications publication_identifier: issn: - 0010-4655 publication_status: published publisher: Elsevier BV status: public title: PHOENIX – Paderborn highly optimized and energy efficient solver for two-dimensional nonlinear Schrödinger equations with integrated extensions type: journal_article user_id: '75963' volume: 315 year: '2025' ... --- _id: '61249' article_number: '024029' author: - first_name: Qiang full_name: Ai, Qiang last_name: Ai - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: Xinmiao full_name: Yang, Xinmiao last_name: Yang - first_name: Jing full_name: Wei, Jing last_name: Wei - first_name: Zaharias full_name: Hatzopoulos, Zaharias last_name: Hatzopoulos - first_name: Pavlos G. full_name: Savvidis, Pavlos G. last_name: Savvidis - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 - first_name: Xuekai full_name: Ma, Xuekai id: '59416' last_name: Ma - first_name: Tingge full_name: Gao, Tingge last_name: Gao citation: ama: Ai Q, Wingenbach J, Yang X, et al. Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice. Physical Review Applied. 2025;23(2). doi:10.1103/physrevapplied.23.024029 apa: Ai, Q., Wingenbach, J., Yang, X., Wei, J., Hatzopoulos, Z., Savvidis, P. G., Schumacher, S., Ma, X., & Gao, T. (2025). Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice. Physical Review Applied, 23(2), Article 024029. https://doi.org/10.1103/physrevapplied.23.024029 bibtex: '@article{Ai_Wingenbach_Yang_Wei_Hatzopoulos_Savvidis_Schumacher_Ma_Gao_2025, title={Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice}, volume={23}, DOI={10.1103/physrevapplied.23.024029}, number={2024029}, journal={Physical Review Applied}, publisher={American Physical Society (APS)}, author={Ai, Qiang and Wingenbach, Jan and Yang, Xinmiao and Wei, Jing and Hatzopoulos, Zaharias and Savvidis, Pavlos G. and Schumacher, Stefan and Ma, Xuekai and Gao, Tingge}, year={2025} }' chicago: Ai, Qiang, Jan Wingenbach, Xinmiao Yang, Jing Wei, Zaharias Hatzopoulos, Pavlos G. Savvidis, Stefan Schumacher, Xuekai Ma, and Tingge Gao. “Optically and Remotely Controlling Localization of Exciton-Polariton Condensates in a Potential Lattice.” Physical Review Applied 23, no. 2 (2025). https://doi.org/10.1103/physrevapplied.23.024029. ieee: 'Q. Ai et al., “Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice,” Physical Review Applied, vol. 23, no. 2, Art. no. 024029, 2025, doi: 10.1103/physrevapplied.23.024029.' mla: Ai, Qiang, et al. “Optically and Remotely Controlling Localization of Exciton-Polariton Condensates in a Potential Lattice.” Physical Review Applied, vol. 23, no. 2, 024029, American Physical Society (APS), 2025, doi:10.1103/physrevapplied.23.024029. short: Q. Ai, J. Wingenbach, X. Yang, J. Wei, Z. Hatzopoulos, P.G. Savvidis, S. Schumacher, X. Ma, T. Gao, Physical Review Applied 23 (2025). date_created: 2025-09-12T11:01:17Z date_updated: 2025-09-12T11:02:33Z department: - _id: '15' - _id: '170' - _id: '297' - _id: '705' - _id: '230' - _id: '35' - _id: '27' doi: 10.1103/physrevapplied.23.024029 intvolume: ' 23' issue: '2' language: - iso: eng project: - _id: '52' name: Computing Resources Provided by the Paderborn Center for Parallel Computing publication: Physical Review Applied publication_identifier: issn: - 2331-7019 publication_status: published publisher: American Physical Society (APS) status: public title: Optically and remotely controlling localization of exciton-polariton condensates in a potential lattice type: journal_article user_id: '16199' volume: 23 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: '51105' author: - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 - first_name: Xuekai full_name: Ma, Xuekai id: '59416' last_name: Ma citation: ama: Wingenbach J, Schumacher S, Ma X. Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems. Physical Review Research, in press. Published online 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, in Press. bibtex: '@article{Wingenbach_Schumacher_Ma_2024, title={Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems}, journal={Physical Review Research, in press}, author={Wingenbach, Jan and Schumacher, Stefan and Ma, Xuekai}, year={2024} }' chicago: Wingenbach, Jan, Stefan Schumacher, and Xuekai Ma. “Manipulating Spectral Topology and Exceptional Points by Nonlinearity in Non-Hermitian Polariton Systems.” Physical Review Research, in Press, 2024. ieee: J. Wingenbach, S. Schumacher, and X. Ma, “Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems,” Physical Review Research, in press, 2024. mla: Wingenbach, Jan, et al. “Manipulating Spectral Topology and Exceptional Points by Nonlinearity in Non-Hermitian Polariton Systems.” Physical Review Research, in Press, 2024. short: J. Wingenbach, S. Schumacher, X. Ma, Physical Review Research, in Press (2024). date_created: 2024-01-31T13:49:29Z date_updated: 2024-01-31T13:52:56Z department: - _id: '15' language: - iso: eng publication: Physical Review Research, in press status: public title: Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems type: journal_article user_id: '59416' year: '2024' ... --- _id: '60023' author: - first_name: Helene full_name: Wetter, Helene last_name: Wetter - first_name: Wenlong full_name: Gao, Wenlong last_name: Gao - first_name: Falk full_name: Rehberg, Falk last_name: Rehberg - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 - first_name: Thomas full_name: Zentgraf, Thomas id: '30525' last_name: Zentgraf orcid: 0000-0002-8662-1101 citation: ama: 'Wetter H, Gao W, Rehberg F, Wingenbach J, Schumacher S, Zentgraf T. Dielectric metasurface for wave-vector variant and circular polarization dependent transmission. In: Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics. ; 2024.' apa: Wetter, H., Gao, W., Rehberg, F., Wingenbach, J., Schumacher, S., & Zentgraf, T. (2024). Dielectric metasurface for wave-vector variant and circular polarization dependent transmission. Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics. META 2024 - The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Toyama, Japan. bibtex: '@inproceedings{Wetter_Gao_Rehberg_Wingenbach_Schumacher_Zentgraf_2024, title={Dielectric metasurface for wave-vector variant and circular polarization dependent transmission}, booktitle={Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics}, author={Wetter, Helene and Gao, Wenlong and Rehberg, Falk and Wingenbach, Jan and Schumacher, Stefan and Zentgraf, Thomas}, year={2024} }' chicago: Wetter, Helene, Wenlong Gao, Falk Rehberg, Jan Wingenbach, Stefan Schumacher, and Thomas Zentgraf. “Dielectric Metasurface for Wave-Vector Variant and Circular Polarization Dependent Transmission.” In Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2024. ieee: H. Wetter, W. Gao, F. Rehberg, J. Wingenbach, S. Schumacher, and T. Zentgraf, “Dielectric metasurface for wave-vector variant and circular polarization dependent transmission,” presented at the META 2024 - The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics, Toyama, Japan, 2024. mla: Wetter, Helene, et al. “Dielectric Metasurface for Wave-Vector Variant and Circular Polarization Dependent Transmission.” Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2024. short: 'H. Wetter, W. Gao, F. Rehberg, J. Wingenbach, S. Schumacher, T. Zentgraf, in: Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics, 2024.' conference: end_date: 2024-07-19 location: Toyama, Japan name: META 2024 - The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics start_date: 2024-07-16 date_created: 2025-05-23T06:30:36Z date_updated: 2025-05-23T06:34:16Z 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 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics publication_identifier: issn: - 2429-1390 status: public title: Dielectric metasurface for wave-vector variant and circular polarization dependent transmission type: conference user_id: '30525' year: '2024' ... --- _id: '61257' abstract: - lang: eng 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 \ " article_number: '013148' author: - first_name: Jan full_name: Wingenbach, Jan id: '69187' last_name: Wingenbach - first_name: Stefan full_name: Schumacher, Stefan id: '27271' last_name: Schumacher orcid: 0000-0003-4042-4951 - first_name: Xuekai full_name: Ma, Xuekai id: '59416' last_name: Ma 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 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 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} }' 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). date_created: 2025-09-12T11:23:33Z date_updated: 2025-09-12T11:24:59Z department: - _id: '15' - _id: '170' - _id: '297' - _id: '705' - _id: '35' - _id: '230' - _id: '27' - _id: '429' doi: 10.1103/physrevresearch.6.013148 intvolume: ' 6' 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: '61' name: 'TRR 142; TP A04: Nichtlineare Quantenprozesstomographie und Photonik mit Polaritonen in Mikrokavitäten' publication: Physical Review Research publication_identifier: issn: - 2643-1564 publication_status: published publisher: American Physical Society (APS) status: public title: Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems type: journal_article user_id: '16199' volume: 6 year: '2024' ...