@article{61279, abstract = {{Spin waves represent an important class of low-energy excitations in magnetic solids, which influence the thermodynamic properties and play a major role in technical applications, such as spintronics or magnetic data storage. Despite the enormous advances of ab initio simulations in materials science, quantitative calculations of spin-wave spectra still pose a significant challenge, because the collective nature of the spin dynamics requires an accurate treatment of the Coulomb interaction between the electrons. As a consequence, simple lattice models like the Heisenberg Hamiltonian are still widespread in practical investigations, but modern techniques like time-dependent density-functional theory or many-body perturbation theory also open a route to material-specific spin-wave calculations from first principles. Although both are in principle exact, actual implementations necessarily employ approximations for electronic exchange and correlation as well as additional numerical simplifications. In this review, we recapitulate the theoretical foundations of ab initio spin-wave calculations and analyze the common approximations that underlie present implementations. In addition, we survey the available results for spin-wave dispersions of various magnetic materials and compare the performance of different computational approaches. In this way, we provide an overview of the present state of the art and identify directions for further developments.}}, author = {{Neugum, Michael and Schindlmayr, Arno}}, issn = {{1996-1944}}, journal = {{Materials}}, number = {{18}}, publisher = {{MDPI}}, title = {{{Ab initio calculations of spin waves: A review of theoretical approaches and applications}}}, doi = {{10.3390/ma18184431}}, volume = {{18}}, year = {{2025}}, } @article{60959, abstract = {{Miller's rule originated as an empirical relation between the nonlinear and linear optical coefficients of materials. It is now accepted as a useful tool for guiding experiments and computational materials discovery, but its theoretical foundation had long been limited to a derivation for the classical Lorentz model with a weak anharmonic perturbation. Recently, we developed a mathematical framework which enabled us to prove that Miller's rule is equally valid for quantum anharmonic oscillators, despite different dynamics due to zero-point fluctuations and further quantum-mechanical effects. However, our previous derivation applied only to one-dimensional oscillators and to the special case of second- and third-harmonic generation in a monochromatic electric field. Here we extend the proof to three-dimensional quantum anharmonic oscillators and also treat all orders of the nonlinear response to an arbitrary multi-frequency field. This makes the results applicable to a much larger range of physical systems and nonlinear optical processes. The obtained generalized Miller formulae rigorously express all tensor elements of the frequency-dependent nonlinear susceptibilities in terms of the linear susceptibility and thus allow a computationally inexpensive quantitative prediction of arbitrary parametric frequency-mixing processes from a small initial dataset.}}, author = {{Meyer, Maximilian Tim and Schindlmayr, Arno}}, issn = {{2673-8716}}, journal = {{Dynamics}}, number = {{3}}, publisher = {{MDPI}}, title = {{{Generalized Miller formulae for quantum anharmonic oscillators}}}, doi = {{10.3390/dynamics5030034}}, volume = {{5}}, year = {{2025}}, } @article{62286, abstract = {{Optical tweezer arrays of laser-cooled and individually controlled particles have revolutionized atomic, molecular, and optical physics. They afford exquisite capabilities for applications in quantum simulation of many-body physics, quantum computation, and sensing. Underlying this development is the technical maturity of generating scalable optical beams, enabled by active components and a high numerical aperture objective. However, such a complex combination of bulk optics outside the vacuum chamber is very sensitive to any vibration and drift. Here, we demonstrate the generation of a 3 × 3 static tweezer array with a single chip-scale multifunctional metasurface element in vacuum, replacing the meter-long free space optics. Fluorescence counts on the camera validate the successful trapping of the atomic ensemble array and showcase a promising strategy for integrated photonics with cold atom systems. The introduction of a polarization independent dual-wavelength metasurface significantly enhances fluorescence collection efficiency while reducing experimental complexity. This approach paves the way for scalable neutral atom platforms and offers a compelling route towards the realization of next generation quantum metasurfaces.}}, author = {{Li, Donghao and Liao, Qiming and Xu, Beining and Zentgraf, Thomas and Narvaez Castaneda, Emmanuel and Zhou, Yaoting and Qin, Keyu and Xu, Zhongxiao and Shen, Heng and Huang, Lingling}}, issn = {{1094-4087}}, journal = {{Optics Express}}, number = {{24}}, publisher = {{Optica Publishing Group}}, title = {{{In vacuum metasurface for optical microtrap array}}}, doi = {{10.1364/oe.580201}}, volume = {{33}}, year = {{2025}}, } @misc{62639, author = {{Kruse, Stephan and Silberhorn, Christine and Brecht, Benjamin and Schwabe, Tobias}}, title = {{{Optisch basierter Digital-Analog-Umsetzer}}}, year = {{2025}}, } @inproceedings{62714, abstract = {{Die fortschreitende Digitalisierung bringt große Herausforderungen für die Aus- und Weiterbildung von Lehrkräften mit sich. Während angehende Lehrkräfte bereits von neuen Entwicklungen in der Ausbildung profitieren, sind viele aktive Lehrkräfte bislang nicht ausreichend auf die digitalen Möglichkeiten im Unterricht vorbereitet. Der Kompetenzverbund lernen:digital setzt genau hier an und unterstützt gezielt Lehrkräfte beim Erwerb digitalisierungsbezogener Kompetenzen. Im Rahmen des Verbundprojekts ComeMINT wurde unter anderem ein Online-Selbstlernkurs entwickelt, der sich mit dem Einsatz digitaler Medien im Physikunterricht befasst. Grundlage des Kurses bilden zum einen eine Bedürfnisanalyse unter praktizierenden Physiklehrkräften und zum anderen bereits bestehende Materialien aus der Lehrkräfteausbildung. Der Kurs vermittelt grundlegende Kompetenzen im Umgang mit physikspezifischen digitalen Medien, wie zum Beispiel digitaler Messwerterfassung, Augmented Reality oder Simulationen. In diesem Beitrag werden die Entwicklung und die Inhalte des Selbstlernkurses skizziert, sowie die nachhaltige Aufbereitung der Materialien zur Nachnutzung dargestellt.}}, author = {{Weiler, David Christoph and Burde, Jan-Philipp and Costan, Kasim and Gieshoff, Rike Isabel and Kulgemeyer, Christoph and Lässer, Armin and Plicht, Katja and Riese, Josef and Schubatzky, Thomas}}, booktitle = {{PhyDid B - Didaktik Der Physik - Beiträge Zur DPG-Frühjahrstagung}}, location = {{Göttingen}}, pages = {{71--78}}, title = {{{Online-Selbstlernkurs zu digitalen Medien im Physikunterricht}}}, year = {{2025}}, } @article{62749, abstract = {{Coherent Raman scattering techniques as coherent anti-Stokes Raman scattering (CARS), offer significant advantages in terms of pixel dwell times and speed as compared to spontaneous Raman scattering for investigations of crystalline materials. However, the spectral information in CARS is often hampered by the presence of a nonresonant contribution to the scattering process that shifts and distorts the Raman peaks. In this work, we apply a method to obtain nonresonant background-free spectra based on time-delayed, broadband CARS (TD-BCARS) using an intrapulse excitation scheme. In particular, this method can measure the phononic dephasing times across the full phonon spectrum at once. We test the methodology on amorphous SiO2 (glass), which is used to characterize the setup-specific and material-independent response times, and then apply TD-BCARS to the analysis of single crystals of diamond and ferroelectrics of potassium titanyl phosphate (KTP) and potassium titanyl arsenate (KTA). For diamond, we determine a dephasing time of 𝜏=7.81 ps for the single 𝑠⁢𝑝3 peak.}}, author = {{Hempel, F. and Rüsing, Michael and Vernuccio, F. and Spychala, K. J. and Buschbeck, R. and Cerullo, G. and Polli, D. and Eng, L. M.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{22}}, publisher = {{American Physical Society (APS)}}, title = {{{Phonon dephasing times determined with time-delayed broadband coherent anti-Stokes Raman scattering}}}, doi = {{10.1103/1ctr-csjy}}, volume = {{112}}, year = {{2025}}, } @article{62867, abstract = {{ABSTRACT Effective manipulation of photonic spin–orbit coupling (SOC) in microcavities is of fundamental importance within topological photonics and applications. Anisotropic organic single‐crystalline materials can induce abundant SOC phenomenon due to their flexible tunability of molecular geometries, however, the intrinsic relationship between molecular geometries/orientations in 3D space and photonic SOC is lacking. In this study, we design two kinds of 2D organic polymorphs for the construction of organic microcavities to investigate the structure‐performance relationships. In two polymorphic microcavities, two distinctive photonic SOC phenomena are observed regardless of the in‐plane anisotropy of organic polymorphs. Theoretical analysis indicates that the photonic SOC strength is strongly influenced by the synergies between the crystal anisotropy and the tilted collective molecular transition dipole moment. Our results uncover the correlation mechanism between the structure of molecules and photonic SOC and open an avenue to engineer complex photonic SOC by use of organic microstructures towards the development of diverse integrated photonic devices.}}, author = {{Ji, Ying and Ma, Xuekai and Huang, Han and Deng, Yibo and Wang, Pingyang and Long, Teng and Li, Yuan and Zhao, Ruiyang and Li, Yunfei and An, Cunbin and Schumacher, Stefan and Gu, Chunling and Liao, Bo and Fu, Hongbing and Liao, Qing}}, issn = {{1863-8880}}, journal = {{Laser & Photonics Reviews}}, publisher = {{Wiley}}, title = {{{Molecular Orientation‐Dependent Photonic Spin–Orbit Coupling in Organic Microcavities Filled with 2D Polymorphic Crystals}}}, doi = {{10.1002/lpor.202501874}}, year = {{2025}}, } @article{62862, abstract = {{Exciton polariton condensates are macroscopic coherent states in which topological excitations can be observed. In this work, we observe the excitation of the vortices and realize tuning the topological charge by manipulating the pumping configurations. Using a digital micromirror device, we constructed an annular pumping pattern where the inner and outer rings can be easily tuned. Both the number and the topological charge of the vortices can be changed by slightly tuning the inner ring position against the outer ring. The experimental results can be reproduced in theory by the Gross–Pitaevskii equation. Our work offers to generate and manipulate vortices in exciton polariton condensates using a straightforward optical method.}}, author = {{Ai, Qiang and Ma, Xuekai and Barkhausen, Franziska and Zhai, Xiaokun and Xing, Chunzi and Yang, Xinmiao and Wang, Peilin and Liu, Tianyu and Zhang, Yong and Gu, Yazhou and Li, Peigang and Li, Zhitong and Hatzopoulos, Zacharias and Savvidis, Pavlos G. and Schumacher, Stefan and Gao, Tingge}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{12}}, publisher = {{AIP Publishing}}, title = {{{Tuning polariton vortices in an asymmetric ring potential}}}, doi = {{10.1063/5.0287076}}, volume = {{127}}, year = {{2025}}, } @article{62865, author = {{Sun, Jinming and Chen, Manna and Schumacher, Stefan and Hu, Wei and Ma, Xuekai}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{11}}, publisher = {{American Physical Society (APS)}}, title = {{{Higher-order dark solitons and control dynamics in microcavity polariton condensates}}}, doi = {{10.1103/p357-vyq8}}, volume = {{112}}, year = {{2025}}, } @article{62860, abstract = {{ The Quantum Internet, a network of quantum-enabled infrastructure, represents the next frontier in telecommunications, promising capabilities that cannot be attained by classical counterparts. A crucial step in realizing such large-scale quantum networks is the integration of entanglement distribution within existing telecommunication infrastructure. Here, we demonstrate a real-world scalable quantum networking testbed deployed within Deutsche Telekom’s metropolitan fibers in Berlin. Using commercially available quantum devices and standard add-drop multiplexing hardware, we distributed polarization-entangled photon pairs over dynamically selectable looped fiber paths ranging from 10 m to 60 km and showed entanglement distribution over up to approximately 100 km. Quantum signals, transmitted at 1324 nm (O-band), coexist with conventional bidirectional C-band traffic without dedicated fibers or infrastructure changes. Active stabilization of the polarization enables robust long-term performance, achieving entanglement Bell-state fidelity bounds between 85% and 99% and Clauser–Horne–Shimony–Holt parameter S -values between 2.36 and 2.74 during continuous multiday operation. By achieving a high-fidelity entanglement distribution with less than 1.5% downtime, we confirm the feasibility of hybrid quantum-classical networks under real-world conditions at the metropolitan scale. These results establish deployment benchmarks and provide a practical roadmap for telecom operators to integrate quantum capabilities. }}, author = {{Sena, Matheus and Flament, Mael and Andrewski, Shane and Caltzidis, Ioannis and Bigagli, Niccolò and Rieser, Thomas and Bello Portmann, Gabriel and Sekelsky, Rourke and Braun, Ralf-Peter and Craddock, Alexander N. and Schulz, Maximilian and Jöns, Klaus and Ritter, Michaela and Geitz, Marc and Holschke, Oliver and Namazi, Mehdi}}, issn = {{1943-0620}}, journal = {{Journal of Optical Communications and Networking}}, number = {{12}}, publisher = {{Optica Publishing Group}}, title = {{{High-fidelity quantum entanglement distribution in metropolitan fiber networks with co-propagating classical traffic}}}, doi = {{10.1364/jocn.575396}}, volume = {{17}}, year = {{2025}}, } @article{62912, abstract = {{We investigate the dynamics of wave packets in a parabolic optical lattice formed by combining an optical lattice with a global parabolic trap. Our study examines the phase space representation of the system's eigenstates by comparing them to the classical phase space of a pendulum, to which the system effectively maps. The analysis reveals that quantum states can exhibit mixed dynamics by straddling the separatrix. A key finding is that the dynamics around the separatrix enables the controlled creation of highly nonclassical states, distinguishing them from the classical oscillatory or rotational dynamics of the pendulum. By considering a finite momentum of the initial wave packet, we demonstrate various dynamical regimes. Furthermore, a slight energy mismatch between nearly degenerate states localized at opposite turning points of the trap potential results in controlled long-range dynamical tunneling. These results can be interpreted as quantum beating between a clockwise rotating and a counterclockwise rotating pendulum.}}, author = {{Ali, Usman and Holthaus, Martin and Meier, Torsten}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, number = {{1}}, publisher = {{American Physical Society (APS)}}, title = {{{Wave packet dynamics in parabolic optical lattices: From Bloch oscillations to long-range dynamical tunneling}}}, doi = {{10.1103/physrevresearch.7.013141}}, volume = {{7}}, year = {{2025}}, } @article{62911, abstract = {{In this paper, we theoretically study the spectral and temporal properties of pulsed spontaneous parametric down-conversion (SPDC) generated in lossy waveguides. Our theoretical approach is based on the formalism of Gaussian states and the Langevin equation, which is elaborated for weak parametric down-conversion and photon-number-unresolved click detection. Using the example of frequency-degenerate type-II SPDC generated under the pump-idler group-velocity-matching condition, we show how the joint-spectral intensity, mode structure, normalized second-order correlation function, and Hong-Ou-Mandel interference pattern depend on internal losses of the SPDC process. We found that the joint-spectral intensity is almost insensitive to internal losses, while the second-order correlation function shows a strong dependence on them, being different for the signal and idler beams in the presence of internal losses. Based on the sensitivity of the normalized second-order correlation function, we show how its measurement can be used to experimentally determine internal losses.}}, author = {{Kopylov, Denis A. and Stefszky, Michael and Meier, Torsten and Silberhorn, Christine and Sharapova, Polina R.}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, number = {{3}}, publisher = {{American Physical Society (APS)}}, title = {{{Spectral and temporal properties of type-II parametric down-conversion: The impact of losses during state generation}}}, doi = {{10.1103/zp72-7qwl}}, volume = {{7}}, year = {{2025}}, } @inproceedings{62913, author = {{Hunstig, Anna and Peitz, Sebastian and Rose, Hendrik and Meier, Torsten}}, booktitle = {{2024 IEEE 63rd Conference on Decision and Control (CDC)}}, publisher = {{IEEE}}, title = {{{Accelerating the analysis of optical quantum systems using the Koopman operator}}}, doi = {{10.1109/cdc56724.2024.10886589}}, year = {{2025}}, } @article{60568, author = {{Bocchini, Adriana and Kollmann, S. and Gerstmann, Uwe and Schmidt, Wolf Gero and Grundmeier, Guido}}, issn = {{0039-6028}}, journal = {{Surface Science}}, publisher = {{Elsevier BV}}, title = {{{Phosphonic acid adsorption on α-Bi2O3 surfaces}}}, doi = {{10.1016/j.susc.2025.122776}}, volume = {{760}}, year = {{2025}}, } @article{61353, abstract = {{Abstract 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 ) 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.}}, author = {{Franzke, Katharina L. and Schmidt, Wolf Gero and Gerstmann, Uwe}}, issn = {{1742-6588}}, journal = {{Journal of Physics: Conference Series}}, number = {{1}}, publisher = {{IOP Publishing}}, title = {{{Finite-size and relativistic effects onto hyperfine interaction of muonic hydrogen}}}, doi = {{10.1088/1742-6596/3027/1/012001}}, volume = {{3027}}, year = {{2025}}, } @inproceedings{61352, author = {{Devaraj, Vasanthan and Ruiz Alvarado, Isaac Azahel and Lee, Jongmin and Oh, Jin-Woo and Gerstmann, Uwe and Schmidt, Wolf Gero and Zentgraf, Thomas}}, booktitle = {{2025 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)}}, publisher = {{IEEE}}, title = {{{Dynamic and Reversible Plasmonic Nanogaps From Isolated Dimer Nanoparticles via Self-Assembly}}}, doi = {{10.1109/cleo/europe-eqec65582.2025.11109762}}, year = {{2025}}, } @article{62866, abstract = {{Abstract The development of efficient and broadly applicable n‐doping strategies for organic semiconductors (OSCs) is crucial for advancing the performance of various organic electronic devices. Here, a novel nucleophilic‐attack n‐doping mechanism is unveiled that achieves exceptionally high conductivity in doped OSC films and demonstrates broad applicability across OSCs. The remarkable efficacy of n‐Butyl lithium (n‐BuLi) is highlighted in n‐doping C 60 and PC 61 BM, achieving a conductivity of 1.27 S cm −1 and 2.57 S cm −1 , respectively, which are among the highest reported values for these materials. The investigation reveals that the n‐BuLi anion interacts with electron‐deficient units in OSCs, generating a carbanion that facilitates efficient electron transfer for n‐doping. This mechanism is further validated across diverse fullerenes, polymeric, and small molecule OSCs, and is extendable to other high‐performance dopants such as tert‐Butyllithium (tert‐BuLi) and sodium ethoxide (NaOEt). Device studies show that n‐BuLi‐doped C 60 enables substantially improved diode rectification, attributed to greater junction built‐in potential. These findings establish a unified chemical‐bonding‐based n‐doping paradigm, complementing existing electrophilic‐attack p‐doping concepts, and pave the way for achieving efficient doping of OSCs for advanced organic electronic applications. }}, author = {{Wei, Huan and Wu, Tong and Dong, Chuanding and Chen, Chen and Gong, Zhenqi and Xia, Jiangnan and Peng, Chengyuan and Ding, Jiaqi and Zhang, Yu and Shi, Wenpei and Schumacher, Stefan and Zhang, Xue and Bai, Yugang and Jiang, Lang and Liao, Lei and Nguyen, Thuc‐Quyen and Hu, Yuanyuan}}, issn = {{2198-3844}}, journal = {{Advanced Science}}, publisher = {{Wiley}}, title = {{{Efficient n‐Doping of Organic Semiconductors via a Broadly Applicable Nucleophilic‐Attack Mechanism}}}, doi = {{10.1002/advs.202520487}}, year = {{2025}}, } @article{60992, abstract = {{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 = {{Wingenbach, Jan and Ares Santos, Laura and Ma, Xuekai and Sperling, Jan and Schumacher, Stefan}}, journal = {{Arxiv}}, publisher = {{Arxiv}}, title = {{{Sensitivity and Topology of Exceptional Rings in Nonlinear Non-Hermitian Planar Optical Microcavities}}}, doi = {{10.48550/ARXIV.2507.07099}}, year = {{2025}}, } @article{62926, abstract = {{Abstract 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, E 2g ) 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 15  defects/cm 3 , offering a powerful tool for optimizing and benchmarking hBN for quantum optical applications. }}, 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}}, issn = {{1616-301X}}, journal = {{Advanced Functional Materials}}, publisher = {{Wiley}}, title = {{{Quantifying Spin Defect Density in hBN via Raman and Photoluminescence Analysis}}}, doi = {{10.1002/adfm.202517851}}, year = {{2025}}, } @article{62980, abstract = {{We introduce a new classification of multimode states with a fixed number of photons. This classification is based on the factorizability of homogeneous multivariate polynomials and is invariant under unitary transformations. The classes physically correspond to field excitations in terms of single and multiple photons, each of which is in an arbitrary irreducible superposition of quantized modes. We further show how the transitions between classes are rendered possible by photon addition, photon subtraction, and photon-projection nonlinearities. We explicitly put forward a design for a multilayer interferometer in which the states for different classes can be generated with state-of-the-art experimental techniques. Limitations of the proposed designs are analyzed using the introduced classification, providing a benchmark for the robustness of certain states and classes.}}, author = {{Kopylov, Denis A. and Offen, Christian and Ares, Laura and Wembe Moafo, Boris Edgar and Ober-Blöbaum, Sina and Meier, Torsten and Sharapova, Polina R. and Sperling, Jan}}, issn = {{2643-1564}}, journal = {{Physical Review Research}}, number = {{3}}, publisher = {{American Physical Society (APS)}}, title = {{{Multiphoton, multimode state classification for nonlinear optical circuits}}}, doi = {{10.1103/sv6z-v1gk}}, volume = {{7}}, year = {{2025}}, }