@unpublished{62979,
  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       = {{Meier, Torsten and Sharapova, Polina R. and Sperling, Jan and Ober-Blöbaum, Sina and Wembe Moafo, Boris Edgar and Offen, Christian}},
  title        = {{{Multiphoton, multimode state classification for nonlinear optical circuits}}},
  year         = {{2025}},
}

@article{63021,
  abstract     = {{<jats:p>Bell measurements, entailing the projection onto one of the Bell states, play a key role in quantum information and communication, where the outcome of a variety of protocols crucially depends on the success probability of such measurements. Although in the case of qubit systems, Bell measurements can be implemented using only linear optical components, the same result is no longer true for qudits, where at least the use of ancillary photons is required. In order to circumvent this limitation, one possibility is to introduce nonlinear effects. In this work, we adopt the latter approach and propose a scalable Bell measurement scheme for high-dimensional states, exploiting multiple squeezer devices applied to a linear optical circuit for discriminating the different Bell states. Our approach does not require ancillary photons, is not limited by the dimension of the quantum states, and is experimentally scalable, thus paving the way toward the realization of an effective high-dimensional Bell measurement.</jats:p>}},
  author       = {{Bianchi, Luca and Marconi, Carlo and Sperling, Jan and Bacco, Davide}},
  issn         = {{2643-1564}},
  journal      = {{Physical Review Research}},
  number       = {{2}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Predetection squeezing as a resource for high-dimensional Bell-state measurements}}},
  doi          = {{10.1103/physrevresearch.7.023038}},
  volume       = {{7}},
  year         = {{2025}},
}

@article{62859,
  abstract     = {{<jats:p>Frequency-filtered photon correlations have been proven to be extremely useful in grasping how the detection process alters photon statistics. Harnessing the spectral correlations also permits refinement of the emission and unraveling of previously hidden strong correlations in a plethora of quantum-optical systems under continuous-wave excitation. In this work, we investigate such correlations for time-dependent excitation and develop a methodology to compute efficiently time-integrated correlations, which are at the heart of the photon-counting theory, and subsequently apply it to analyze the photon emission of pulsed systems. By combining this formalism with the —which facilitates frequency-resolved correlations—we demonstrate how spectral filtering enhances single-photon purity and suppresses multiphoton noise in time-bin-encoded quantum states. Specifically, filtering the central spectral peak of a dynamically driven two-level system boosts temporal coherence and improves the fidelity of time-bin entanglement preparation, even under conditions favoring multiphoton emission. These results establish spectral filtering as a critical tool for tailoring photon statistics in pulsed quantum light sources.</jats:p>}},
  author       = {{Bermúdez-Feijóo, Santiago and Zubizarreta Casalengua, Eduardo and Müller, Kai and Jöns, Klaus}},
  issn         = {{2643-1564}},
  journal      = {{Physical Review Research}},
  number       = {{3}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Spectral correlations of dynamical resonance fluorescence}}},
  doi          = {{10.1103/jmy9-bd3l}},
  volume       = {{7}},
  year         = {{2025}},
}

@article{63160,
  author       = {{Rose, Hendrik and Schumacher, Stefan and Meier, Torsten}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{24}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Microscopic approach to the quantized light-matter interaction in semiconductor nanostructures: Complex coupled dynamics of excitons, biexcitons, and photons}}},
  doi          = {{10.1103/528f-7smh}},
  volume       = {{112}},
  year         = {{2025}},
}

@article{62861,
  author       = {{Laneve, Alessandro and Ronco, Giuseppe and Beccaceci, Mattia and Barigelli, Paolo and Salusti, Francesco and Claro-Rodriguez, Nicolas and De Pascalis, Giorgio and Suprano, Alessia and Chiaudano, Leone and Schöll, Eva and Hanschke, Lukas and Krieger, Tobias M. and Buchinger, Quirin and Covre da Silva, Saimon F. and Neuwirth, Julia and Stroj, Sandra and Höfling, Sven and Huber-Loyola, Tobias and Usuga Castaneda, Mario A. and Carvacho, Gonzalo and Spagnolo, Nicolò and Rota, Michele B. and Basso Basset, Francesco and Rastelli, Armando and Sciarrino, Fabio and Jöns, Klaus and Trotta, Rinaldo}},
  issn         = {{2041-1723}},
  journal      = {{Nature Communications}},
  number       = {{1}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Quantum teleportation with dissimilar quantum dots over a hybrid quantum network}}},
  doi          = {{10.1038/s41467-025-65911-9}},
  volume       = {{16}},
  year         = {{2025}},
}

@article{63534,
  abstract     = {{<jats:p>Boson sampling is a key candidate for demonstrating quantum advantage and has already yielded significant advances in quantum simulation, machine learning, and graph theory. In this work, a unification and extension of distinct forms of boson sampling is developed. The devised protocol merges discrete-variable scattershot boson sampling with continuous-variable Gaussian boson sampling. Therefore, it is rendered possible to harness the complexity of more interesting states, such as squeezed photons, in advanced sampling protocols. A generating function formalism is developed for the joint description of multiphoton and multimode light undergoing Gaussian transformations. The resulting analytical tools enable one to explore interfaces of different photonic quantum-information-processing platforms. A numerical simulation of unified sampling is carried out, benchmarking its performance, complexity, and scalability. Entanglement is characterized to exemplify the generation of quantum correlations from the nonlinear interactions of a unified sampler.</jats:p>}},
  author       = {{Bianchi, Luca and Marconi, Carlo and Ares, Laura and Bacco, Davide and Sperling, Jan}},
  issn         = {{2643-1564}},
  journal      = {{Physical Review Research}},
  number       = {{4}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Unified boson sampling}}},
  doi          = {{10.1103/8hy1-m5gg}},
  volume       = {{7}},
  year         = {{2025}},
}

@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}},
}

@article{60566,
  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}},
  issn         = {{2475-9953}},
  journal      = {{Physical Review Materials}},
  number       = {{7}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Mg dopants in lithium niobate: Defect models and impact on domain inversion}}},
  doi          = {{10.1103/5wz1-bjyr}},
  volume       = {{9}},
  year         = {{2025}},
}

@article{54093,
  author       = {{Pinske, Julien and Sperling, Jan}},
  issn         = {{2469-9926}},
  journal      = {{Physical Review A}},
  number       = {{5}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Unbreakable and breakable quantum censorship}}},
  doi          = {{10.1103/physreva.109.052408}},
  volume       = {{109}},
  year         = {{2024}},
}

@article{55140,
  author       = {{Yasmin, Farha and Sperling, Jan}},
  issn         = {{2469-9926}},
  journal      = {{Physical Review A}},
  number       = {{1}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Entanglement-assisted quantum speedup: Beating local quantum speed limits}}},
  doi          = {{10.1103/physreva.110.012424}},
  volume       = {{110}},
  year         = {{2024}},
}

@article{55173,
  author       = {{Di Fidio, Christian and Ares, Laura and Sperling, Jan}},
  issn         = {{2469-9926}},
  journal      = {{Physical Review A}},
  number       = {{1}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Quantum walks and entanglement in cavity networks}}},
  doi          = {{10.1103/physreva.110.013705}},
  volume       = {{110}},
  year         = {{2024}},
}

@article{55267,
  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.}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{7}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Optical Stark effect in type-II semiconductor heterostructures}}},
  doi          = {{10.1103/physrevb.109.075301}},
  volume       = {{109}},
  year         = {{2024}},
}

@article{54668,
  abstract     = {{Samples of dielectric optical waveguides of rib or strip type in thin-film lithium niobate (TFLN) technology are characterized with respect to their optical loss using the Fabry-Pérot method. Attributing the losses mainly to sidewall roughness, we employ a simple perturbational procedure, based on rigorously computed mode profiles of idealized channels, to estimate the attenuation for waveguides with different cross sections. A single fit parameter suffices for an adequate modelling of the effect of the waveguide geometry on the loss levels.}},
  author       = {{Hammer, Manfred and Babel, Silia and Farheen, Henna and Padberg, Laura and Scheytt, J. Christoph and Silberhorn, Christine and Förstner, Jens}},
  issn         = {{1094-4087}},
  journal      = {{Optics Express}},
  keywords     = {{tet_topic_waveguide}},
  number       = {{13}},
  pages        = {{22878}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Estimation of losses caused by sidewall roughness in thin-film lithium niobate rib and strip waveguides}}},
  doi          = {{10.1364/oe.521766}},
  volume       = {{32}},
  year         = {{2024}},
}

@article{55751,
  abstract     = {{Lateral leakage of TM modes in dielectric optical waveguides of rib/ridge or strip-loaded types can be fully suppressed, if the waveguide core is formed not through a strip that protrudes at one side (up) from the remaining lateral guiding slab, but through parallel strips on both sides (up and down), such that the resulting cross section becomes vertically symmetric. The fairly general arguments underlying the leakage suppression apply to TM modes of all orders simultaneously, and are independent of wavelength. These plus-shaped waveguides support strictly guided, non-leaky TM modes for, in principle, arbitrarily shallow etching.}},
  author       = {{Üstün, Necati and Farheen, Henna and Hammer, Manfred and Förstner, Jens}},
  issn         = {{0740-3224}},
  journal      = {{Journal of the Optical Society of America B}},
  keywords     = {{tet_topic_waveguide}},
  number       = {{9}},
  pages        = {{2077}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Symmetry-protected TM modes in rib-like, plus-shaped optical waveguides with shallow etching}}},
  doi          = {{10.1364/josab.528729}},
  volume       = {{41}},
  year         = {{2024}},
}

@inproceedings{55268,
  author       = {{Rose, Hendrik and Sharapova, Polina R. and Meier, Torsten}},
  booktitle    = {{Ultrafast Phenomena and Nanophotonics XXVIII}},
  editor       = {{Betz, Markus and Elezzabi, Abdulhakem Y.}},
  publisher    = {{SPIE}},
  title        = {{{Microscopic simulations of the dynamics of excitonic many-body correlations coupled to quantum light}}},
  doi          = {{10.1117/12.2690245}},
  year         = {{2024}},
}

@article{55989,
  abstract     = {{Phased arrays are vital in communication systems and have received significant interest in the field of optoelectronics and photonics, enabling a wide range of applications such as LiDAR, holography, wireless communication, etc. In this work, we present a blazed grating antenna that is optimized to have upward radiation efficiency as high as 80% with a compact footprint of 3.5 μm × 2 μm at an operational wavelength of 1.55 μm. Our numerical investigations demonstrate that this antenna in a 64 × 64 phased array configuration is capable of producing desired far-field radiation patterns. Additionally, our antenna possesses a low side lobe level of -9.7 dB and a negligible reflection efficiency of under 1%, making it an attractive candidate for integrated optical phased arrays.}},
  author       = {{Farheen, Henna and Joshi, Suraj and Scheytt, J. Christoph and Myroshnychenko, Viktor and Förstner, Jens}},
  issn         = {{2515-7647}},
  journal      = {{Journal of Physics: Photonics}},
  keywords     = {{tet_topic_opticalantenna}},
  pages        = {{045010}},
  publisher    = {{IOP Publishing}},
  title        = {{{An efficient compact blazed grating antenna for optical phased arrays}}},
  doi          = {{10.1088/2515-7647/ad6ed4}},
  volume       = {{6}},
  year         = {{2024}},
}

@article{56193,
  abstract     = {{Dielectric slab waveguides made of thin-film-lithium-niobate (TFLN) media are consid-ered, for operation in the linear regime. We outline and implement a largely analytic procedure forrigorous modal analysis of three-layer slabs with birefringent, anisotropic core. For Z-cut wave-guides, the slab eigenmode problem separates into uncoupled sets of scalar equations for TE andTM modes. Slabs in X-cut configuration support mostly mildly hybrid eigenmodes, with clear pre-dominant TE or TM polarization, and with effective indices that depend on the propagation directionof the modes, relative to the crystal axes. Strong hybridization can be observed for near degeneratemodes in singular configurations without vertical symmetry, or in symmetric slabs where two nearlydegenerate modes are of the same symmetry class. Dispersion curves for slab thickness and propa-gation angle are discussed, for slabs with oxide and air cover. }},
  author       = {{Hammer, Manfred and Farheen, Henna and Förstner, Jens}},
  issn         = {{2770-0208}},
  journal      = {{Optics Continuum}},
  keywords     = {{tet_topic_waveguide}},
  pages        = {{532822}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Guided modes of thin-film lithium niobate slabs}}},
  doi          = {{10.1364/optcon.532822}},
  year         = {{2024}},
}

@article{58218,
  author       = {{Grisard, Stefan  and Trifonov, Artur V.  and Hahn, Thilo and Kuhn, Tilmann  and Hordiichuk, Oleh  and Kovalenko, Maksym V.  and Yakovlev, Dmitri R.  and Bayer, Manfred  and Akimov, Ilya A. }},
  journal      = {{ACS Photonics}},
  number       = {{8}},
  title        = {{{Spin-Dependent Exciton–Exciton Interactions in a Mixed Lead Halide Perovskite Crystal}}},
  doi          = {{https://doi.org/10.1021/acsphotonics.4c00499}},
  volume       = {{11}},
  year         = {{2024}},
}

@inproceedings{60023,
  author       = {{Wetter, Helene and Gao, Wenlong and Rehberg, Falk and Wingenbach, Jan and Schumacher, Stefan and Zentgraf, Thomas}},
  booktitle    = {{Proceedings of The 14th International Conference on Metamaterials, Photonic Crystals and Plasmonics}},
  issn         = {{2429-1390}},
  location     = {{Toyama, Japan}},
  title        = {{{Dielectric metasurface for wave-vector variant and circular polarization dependent transmission}}},
  year         = {{2024}},
}

@article{57410,
  author       = {{Röder, J. and Gerhard, M. and Fuchs, C. and Stolz, W. and Heimbrodt, W. and Koch, M. and Ngo, C. and Steiner, J. T. and Meier, Torsten}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{19}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Charge transfer magnetoexcitons in magnetoabsorption spectra of asymmetric type-II double quantum wells}}},
  doi          = {{10.1103/physrevb.110.195306}},
  volume       = {{110}},
  year         = {{2024}},
}