@article{63562,
  abstract     = {{<jats:p>Entangled two-mode Gaussian states constitute an important building block for continuous variable quantum computing and communication protocols. In this work, we theoretically study two-mode bipartite states, which are extracted from multimode light generated via type-II parametric downconversion (PDC) in lossy waveguides. For these states, we demonstrate that the squeezing quantifies entanglement and we construct a measurement basis, which results in the maximal bipartite entanglement. We illustrate our findings by numerically solving the spatial master equation for PDC in a Markovian environment. The optimal measurement modes are compared with two widely used broadband bases: the Mercer–Wolf basis (the first-order coherence basis) and the Williamson–Euler basis.</jats:p>}},
  author       = {{Kopylov, Denis and Meier, Torsten and Sharapova, Polina R.}},
  issn         = {{2835-0103}},
  journal      = {{APL Quantum}},
  number       = {{4}},
  publisher    = {{AIP Publishing}},
  title        = {{{Bipartite entanglement extracted from multimode squeezed light generated in lossy waveguides}}},
  doi          = {{10.1063/5.0293116}},
  volume       = {{2}},
  year         = {{2025}},
}

@unpublished{57235,
  author       = {{Weiler, David and Burde, Jan-Philipp and Costan, Kasim and Große-Heilmann, Rike Isabel and Kulgemeyer, Christoph and Lässer, Armin and Riese, Josef and Schubatzky, Thomas}},
  booktitle    = {{Lernen, lehren und forschen im Schülerlabor. Gesellschaft Für Didaktik Der Chemie Und Physik Jahrestagung 2024 in Bochum}},
  title        = {{{Bedürfnisse von Lehrkräften zu digitalen Medien adressieren! }}},
  year         = {{2025}},
}

@unpublished{58544,
  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 being 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 and Offen, Christian and Ares, Laura and Wembe Moafo, Boris Edgar and Ober-Blöbaum, Sina and Meier, Torsten and Sharapova, Polina and Sperling, Jan}},
  title        = {{{Multiphoton, multimode state classification for nonlinear optical circuits }}},
  year         = {{2025}},
}

@article{58885,
  abstract     = {{There have been several attempts to conceptualize and operationalize pedagogical content knowledge (PCK) in the context of teachers' professional competencies. A recent and popular model is the Refined Consensus Model (RCM), which proposes a framework of dispositional competencies (personal PCK—pPCK) that influence more action-related competencies (enacted PCK—ePCK) and vice versa. However, descriptions of the internal structure of pPCK and possible knowledge domains that might develop independently are still limited, being either primarily theoretically motivated or strictly hierarchical and therefore of limited use, for example, for formative feedback and further development of the RCM. Meanwhile, a non-hierarchical differentiation for the ePCK regarding the plan-teach-reflect cycle has emerged. In this study, we present an exploratory computational approach to investigate pre-service teachers' pPCK for a similar non-hierarchical structure using a large dataset of responses to a pPCK questionnaire (N=846). We drew on theoretical foundations and previous empirical findings to achieve interpretability by integrating this external knowledge into our analyses using the Computational Grounded Theory (CGT) framework. The results of a cluster analysis of the pPCK scores indicate the emergence of prototypical groups, which we refer to as competency profiles: (1) a group with low performance, (2) a group with relatively advanced competency in using pPCK to create instructional elements, (3) a group with relatively advanced competency in using pPCK to assess and analyze described instructional elements, and (4) a group with high performance. These groups show tendencies for certain language usage, which we analyze using a structural topic model in a CGT-inspired pattern refinement step. We verify these patterns by demonstrating the ability of a machine learning model to predict the competency profile assignments. Finally, we discuss some implications of the results for the further development of the RCM and their potential usability for an automated formative assessment.}},
  author       = {{Zeller, Jannis and Riese, Josef}},
  issn         = {{1098-2736}},
  journal      = {{Journal of Research in Science Teaching}},
  keywords     = {{computational grounded theory, language analysis, machine learning, pedagogical content knowledge, unsupervised learning}},
  title        = {{{Competency Profiles of PCK Using Unsupervised Learning: What Implications for the Structures of pPCK Emerge From Non-Hierarchical Analyses?}}},
  doi          = {{10.1002/tea.70001}},
  year         = {{2025}},
}

@article{58907,
  author       = {{Hörnlein, Madeleine}},
  journal      = {{die hochschullehre}},
  title        = {{{Physik lernen durch Erklären? - Evaluation eines Seminarkonzepts für Sachunterrichtsstudierende}}},
  doi          = {{https://dx.doi.org/10.3278/HSL2462W}},
  volume       = {{11}},
  year         = {{2025}},
}

@article{58658,
  author       = {{Webersen, Yvonne and Riese, Josef}},
  journal      = {{HLZ – Herausforderung Lehrer*innenbildung}},
  number       = {{1}},
  title        = {{{Umdenken! Vom fachlichen zum schulischen Experimentieren. Vorstellung einer Lehrkonzeption für angehende Physiklehrkräfte. }}},
  doi          = {{10.11576/hlz-7118}},
  volume       = {{8}},
  year         = {{2025}},
}

@article{58977,
  author       = {{Schubatzky, Thomas and Burde, Jan-Philipp and Große-Heilmann, Rike Isabel and Lachner, Andreas and Riese, Josef and Weiler, David}},
  issn         = {{2666-5573}},
  journal      = {{Computers and Education Open}},
  publisher    = {{Elsevier BV}},
  title        = {{{From Knowledge To Intention: The Role Of TPACK And Self-Efficacy In Technology Integration}}},
  doi          = {{10.1016/j.caeo.2025.100246}},
  year         = {{2025}},
}

@article{59069,
  abstract     = {{<jats:p>Stable and bright single photon sources are key components for future quantum applications. A simple fabrication method is an important requirement for such sources. Here, we present a single photon source based on diced ridge waveguides in titanium indiffused LiNbO<jats:sub>3</jats:sub>. These waveguides can be easily fabricated by combining planar titanium in-diffusion without lithographic patterning and easy-to-handle precision dicing. Such devices have the potential to generate high single photon rates because ridge structures are typically less prone to the photorefractive effect. We achieve waveguide propagation losses &lt;0.4dBcm and a SHG conversion efficiency of about 81%Wcm<jats:sup>2</jats:sup>. Harnessing a type-0 SPDC process to generate 1550 nm photons, we obtain a SPDC brightness of 3⋅10<jats:sup>5</jats:sup>1s⋅mW⋅nm, with a heralding efficiency of <jats:italic>η</jats:italic><jats:sub>h</jats:sub>=45% (<jats:italic>η</jats:italic><jats:sub>h,wg</jats:sub>=77.5% for the waveguide itself excluded setup losses) and a heralded second-order correlation function of <jats:italic>g</jats:italic><jats:sub>h</jats:sub><jats:sup>2</jats:sup>(0)&lt;0.003 at low pump powers.</jats:p>}},
  author       = {{Kießler, Christian and Kirsch, Michelle and Lengeling, Sebastian and Herrmann, Harald and Silberhorn, Christine}},
  issn         = {{2770-0208}},
  journal      = {{Optics Continuum}},
  number       = {{3}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{SPDC single-photon source in Ti-indiffused diced ridge LiNbO<sub>3</sub> waveguides}}},
  doi          = {{10.1364/optcon.557439}},
  volume       = {{4}},
  year         = {{2025}},
}

@article{59176,
  abstract     = {{Das fachdidaktische Wissen (FDW) stellt eine wichtige Komponente des Professionswissens von (angehenden) Lehrkräften dar. Es liegen bereits empirische Forschungsergebnisse zu Einflussfaktoren und zur Entwicklung des FDW sowie zur Bedeutung des FDW als Ganzem für Professionswissen und Qualität professioneller Handlungen vor. Für eine detailliertere Forschung zur Zusammenhangsstruktur zwischen FDW und der Performanz in prototypischen Handlungssituationen sind darüber hinaus differenziertere empirisch begründete Beschreibungen der inneren Struktur des FDW notwendig. Bisher sind entsprechende Ansätze allerdings zumeist primär theoretisch-normativ begründet oder auf hierarchische Betrachtungen beschränkt. Im vorliegenden Beitrag wird daher ein Ansatz zur nicht-hierarchischen datenbasierten Beschreibung latenter Kompetenzprofile des FDW orientiert an der Computational Grounded Theory vorgestellt. Dabei wird zunächst mithilfe eines Datensatzes von 846 Bearbeitungen des Physik-FDW-Testinstruments in überwiegend offenem Antwortformat aus dem Projekt ProfiLe-P+ eine latente Profilanalyse zur Untersuchung latenter FDW-Profile unter Fokus auf kognitive Anforderungen als empirisch trennbare Subskalen des FDW durchgeführt. Mithilfe von Topic Modeling werden anschließend Tendenzen in der Sprachnutzung der FDW-Profile untersucht. Um die Ergebnisse im Sinne der Computational Grounded Theory durch den Nachweis latenter Zusammenhänge zwischen den Testantworten der Proband:innen und der FDW-Profil-Zuordnung zu bestätigen, wird im Anschluss ein Machine-Learning-basiertes System zur automatisierten Zuordnung von Testbearbeitungen zu den FDW-Profilen erstellt. Es zeigen sich vier latente Kompetenzprofile mit nicht-hierarchischem Charakter. In einer längsschnittlichen Betrachtung wird abschließend die Entwicklung von Proband:innen im Kontext dieser FDW-Profile dargestellt. Die Ergebnisse bieten Ansatzmöglichkeiten zukünftig Untersuchungen der Zusammenhänge einzelner FDW-Komponenten und beispielsweise gezeigter Handlungsqualität auf Detailebene zu untersuchen.}},
  author       = {{Zeller, Jannis and Riese, Josef}},
  issn         = {{0949-1147}},
  journal      = {{Zeitschrift für Didaktik der Naturwissenschaften}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Machine-Learning basierte Analyse von latenten Profilen des physikdidaktischen Wissens Machine-Learning-Based Analysis of Latent Profiles in Physics PCK}}},
  doi          = {{10.1007/s40573-025-00181-y}},
  volume       = {{31}},
  year         = {{2025}},
}

@article{59276,
  abstract     = {{Stress plays a crucial role in thin films and layered systems, and thus significantly influences the material's electrical, mechanical and (nonlinear) optical responses. Despite lithium niobate's wide applicability as a nonlinear optical material, the impact of mechanical stress on its nonlinear optical properties is not well characterized. In this work, we systematically study both experimentally and theoretically, the nonlinear optical responses of thin film lithium niobate (TFLN) single crystals. Compressive and tensile stress is applied in our experiment using a piezodriven strain cell. We then record the second-harmonic-generated (SHG) response in back-reflection geometry, and compare these results to theoretical modeling using density functional theory (DFT). Both methods consistently reveal that uniaxial stress induces changes of the nonlinear optical susceptibility of certain tensor elements on the order of up to 1 pm/(V GPa). The exact value depends on the tensor element that is addressed in our SHG analysis, on the crystal orientation, and also whether using compressive or tensile stresses. Furthermore, a lowering of the crystal symmetry when applying stress along the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>x</a:mi></a:math> or <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>y</b:mi></b:math> crystallographic axes is observed by the appearance of new nonlinear optical tensor elements within the strained crystals.}},
  author       = {{Pionteck, Mike N. and Roeper, Matthias and Koppitz, Boris and Seddon, Samuel D. and Rüsing, Michael and Padberg, Laura and Eigner, Christof and Silberhorn, Christine and Sanna, Simone and Eng, Lukas M.}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{6}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Second-order nonlinear piezo-optic properties of single crystal lithium niobate thin films}}},
  doi          = {{10.1103/physrevb.111.064109}},
  volume       = {{111}},
  year         = {{2025}},
}

@article{60511,
  author       = {{Kulgemeyer, Christoph and Hörnlein, Madeleine}},
  journal      = {{Plus Lucis}},
  pages        = {{10--12}},
  title        = {{{Zwischen Verstehensillusion und Wissenserwerb}}},
  volume       = {{2}},
  year         = {{2025}},
}

@article{60565,
  author       = {{Bocchini, Adriana and Gerstmann, Uwe and Schmidt, Wolf Gero}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{10}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Microscopic origin of gray tracks in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>KTiOPO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:math>}}},
  doi          = {{10.1103/physrevb.111.104103}},
  volume       = {{111}},
  year         = {{2025}},
}

@article{60580,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>AlInP (001) is widely utilized as a window layer in optoelectronic devices, including world‐record III‐V multi‐junction solar cells and photoelectrochemical (PEC) cells. The chemical and electronic properties of AlInP (001) depend on its surface reconstruction, which impacts its interaction with electrolytes in PEC applications and passivation layers. This study investigates AlInP (001) surface reconstructions using density functional theory and experimental methods. Phosphorus‐rich (P‐rich) and indium‐rich (In‐rich) AlInP surfaces are prepared with in situ monitoring of the process by reflection anisotropy (RA) spectroscopy and confirmed by low‐energy electron diffraction and photoemission spectroscopy. The experimental RA spectra closely match the theoretical predictions obtained by solving the Bethe–Salpeter equation. It is shown that missing hydrogen on P‐rich surfaces and formation of In–In 1D atomic chains on In‐rich surfaces introduce mid‐gap surface states that pin the Fermi level and induce band bending. Time‐resolved two‐photon photoemission measurements reveal ultrafast near‐surface electron dynamics for both P‐rich and In‐rich surfaces, demonstrating photoexcited electrons reaching the surface conduction band minimum and relaxing to mid‐gap surface states on about hundreds of fs. This work provides the most extensive AlInP surface analysis to date, allowing for more targeted surface and interface engineering, which is crucial for the optimization and design of III‐V heterostructures.</jats:p>}},
  author       = {{Zare Pour, Mohammad Amin and Shekarabi, Sahar and Ruiz Alvarado, Isaac Azahel and Diederich, Jonathan and Gao, Yuyings and Paszuk, Agnieszka and Moritz, Dominik C. and Jaegermann, Wolfram and Friedrich, Dennis and van de Krol, Roel and Schmidt, Wolf Gero and Hannappel, Thomas}},
  issn         = {{1616-301X}},
  journal      = {{Advanced Functional Materials}},
  publisher    = {{Wiley}},
  title        = {{{Exploring Electronic States and Ultrafast Electron Dynamics in AlInP Window Layers: The Role of Surface Reconstruction}}},
  doi          = {{10.1002/adfm.202423702}},
  year         = {{2025}},
}

@article{58642,
  abstract     = {{We present a cost-effective self-assembly method to fabricate low-density dimer NPs in an NPoM architecture, using the M13 phage as a spacer layer. This will enable the development of dynamic plasmonic devices and advanced sensing applications.}},
  author       = {{Devaraj, Vasanthan and Ruiz Alvarado, Isaac Azahel and Lee, Jong-Min and Oh, Jin-Woo and Gerstmann, Uwe and Schmidt, Wolf Gero and Zentgraf, Thomas}},
  issn         = {{2055-6756}},
  journal      = {{Nanoscale Horizons}},
  pages        = {{537--548}},
  publisher    = {{Royal Society of Chemistry (RSC)}},
  title        = {{{Self-assembly of isolated plasmonic dimers with sub-5 nm gaps on a metallic mirror}}},
  doi          = {{10.1039/d4nh00546e}},
  volume       = {{10}},
  year         = {{2025}},
}

@inproceedings{60587,
  author       = {{Schapeler, Timon and Schlue, Fabian and Stefszky, Michael and Brecht, Benjamin and Silberhorn, Christine and Bartley, Tim}},
  booktitle    = {{Advanced Photon Counting Techniques XIX}},
  editor       = {{Itzler, Mark A. and McIntosh, K. Alex and Bienfang, Joshua C.}},
  publisher    = {{SPIE}},
  title        = {{{Optimizing photon-number resolution with superconducting nanowire multi-photon detectors}}},
  doi          = {{10.1117/12.3054905}},
  year         = {{2025}},
}

@inproceedings{35659,
  author       = {{Webersen, Yvonne and Riese, Josef}},
  booktitle    = {{Entdecken, lehren und forschen im Schülerlabor. Gesellschaft für Didaktik der Chemie und Physik. Jahrestagung in Bochum 2024}},
  editor       = {{van Vorst, Helena}},
  pages        = {{764--767}},
  title        = {{{„Die Erde ist eine Scheibe und wir waren nie auf dem Mond!“?  Ein Seminar zur Nature of Science und Techniken der Wissenschaftsleugnung}}},
  year         = {{2025}},
}

@phdthesis{60589,
  author       = {{Große-Heilmann, Rike Isabel}},
  pages        = {{387}},
  publisher    = {{Logos Verlag Berlin}},
  title        = {{{Entwicklung fachdidaktischen Wissens zum Einsatz digitaler Medien im Fach Physik}}},
  doi          = {{https://doi.org/10.30819/5943}},
  volume       = {{388}},
  year         = {{2025}},
}

@inproceedings{60734,
  author       = {{Weiler, David Christoph and Burde, Jan-Philipp and Costan, Kasim and Große-Heilmann, Rike Isabel and Kulgemeyer, Christoph and Lässer, Armin and Riese, Josef and Schubatzky, Thomas }},
  booktitle    = {{Lernen, lehren und forschen im Schülerlabor}},
  location     = {{Bochum}},
  title        = {{{Bedürfnisse von Lehrkräften zu digitalen Medien adressieren! }}},
  year         = {{2025}},
}

@article{36889,
  author       = {{Webersen, Yvonne and Köthemann, Maite}},
  journal      = {{Naturwissenschaften im Unterricht Physik }},
  number       = {{207/208}},
  pages        = {{92--94}},
  publisher    = {{Friedrich Verlag}},
  title        = {{{Wie experimentieren eigentlich Physiker:innen? Einblicke in Forschungsprozesse mithilfe von Videointerviews }}},
  year         = {{2025}},
}

@inproceedings{57760,
  author       = {{Hörnlein, Madeleine and Riese, Josef and Kulgemeyer, Christoph}},
  booktitle    = {{Lernen, Lehren und Forschen im Schülerlabor. Jahrestagung der Gesellschaft für Didaktik der Chemie und Physik 2024}},
  editor       = {{van Vorst, Helena}},
  location     = {{Bochum }},
  title        = {{{"Ich glaub, ich hab's verstanden." - Verstehensillusion bei Erklärvideos}}},
  year         = {{2025}},
}