@unpublished{47533,
  abstract     = {{The control and active manipulation of spin-orbit coupling (SOC) in photonic
systems is fundamental in the development of modern spin optics and topological
photonic devices. Here, we demonstrate the control of an artificial
Rashba-Dresselhaus (RD) SOC mediated by photochemical reactions in a
microcavity filled with an organic single-crystal of photochromic phase-change
character. Splitting of the circular polarization components of the optical
modes induced by photonic RD SOC is observed experimentally in momentum space.
By applying an ultraviolet light beam, we control the spatial molecular
orientation through a photochemical reaction and with that we control the
energies of the photonic modes. This way we realize a reversible conversion of
spin-splitting of the optical modes with different energies, leading to an
optically controlled switching between circularly and linearly polarized
emission from our device. Our strategy of in situ and reversible engineering of
SOC induced by a light field provides a promising approach to actively design
and manipulate synthetic gauge fields towards future on-chip integration in
photonics and topological photonic devices.}},
  author       = {{Liang, Qian and Ma, Xuekai and Ren, Jiahuan and Long, Teng and Gu, Chunling and An, Cunbin and Fu, Hongbing and Schumacher, Stefan and Liao, Qing}},
  booktitle    = {{arXiv:2309.07652}},
  title        = {{{Photochemical reaction enabling the engineering of photonic spin-orbit
  coupling in organic-crystal optical microcavities}}},
  year         = {{2023}},
}

@unpublished{47531,
  abstract     = {{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-Andr\'e-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 horizontal
and SSH chains in the vertical direction then results in the formation of
higher-order topological insulator corner states.}},
  author       = {{Schneider, Tobias and Gao, Wenlong and Zentgraf, Thomas and Schumacher, Stefan and Ma, Xuekai}},
  booktitle    = {{arXiv:2303.12593}},
  title        = {{{Topological edge and corner states in coupled wave lattices in nonlinear  polariton condensates}}},
  year         = {{2023}},
}

@unpublished{47529,
  abstract     = {{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 theoretically demonstrate the realization of EPs in a system
with significant nonlinearity, a non-equilibrium 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, we also observe intriguing rotations and intersections of
Riemann surfaces, and find nonlinearity-enhanced sensing capabilities. Our
results are quite general in nature and illustrate the potential of tailoring
spectral topology and related phenomena in non-Hermitian systems by
nonlinearity.}},
  author       = {{Wingenbach, Jan and Schumacher, Stefan and Ma, Xuekai}},
  booktitle    = {{arXiv:2305.04855}},
  title        = {{{Tweaking Spectral Topology and Exceptional Points by Nonlinearity in
  Non-Hermitian Polariton Systems}}},
  year         = {{2023}},
}

@inproceedings{45577,
  author       = {{Webersen, Yvonne}},
  booktitle    = {{Lernen, Lehren und Forschen in  einer digital geprägten Welt. Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022}},
  editor       = {{van Vorst, Helena}},
  pages        = {{750--753}},
  title        = {{{Entwicklung und Evaluation einer NdN-Unterrichtsreihe zur Unterstützung von Lernpfaden}}},
  year         = {{2023}},
}

@inbook{47543,
  author       = {{Zentgraf, Thomas and Sain, Basudeb and Zhang, Shuang}},
  booktitle    = {{Fundamentals and Applications of Nonlinear Nanophotonics}},
  editor       = {{Panoiu, Nicoae C.}},
  isbn         = {{978-0-323-90614-2}},
  publisher    = {{Elsevier}},
  title        = {{{Symmetry governed nonlinear selection rules in nanophotonics }}},
  doi          = {{10.1016/B978-0-323-90614-2.00011-0}},
  year         = {{2023}},
}

@article{40513,
  abstract     = {{Geometric-phase dielectric meta-lenses made of silicon with high numerical aperture and short focal lengths are fabricated and characterised. For circularly polarised light, the same meta-lens can act as a converging or diverging lens, depending on the handedness of the circular polarisation. This effect enables application for optical tweezers that trap or release µm-size polymer beads floating in a microfluidic channel on demand. An electrically addressable polarisation converter based on liquid crystals may be used to switch between the two states of polarisation, at which the light transmitted through the meta-lens is focused (trapping) or defocussed (releasing), respectively.}},
  author       = {{Geromel, René and Rennerich, Roman and Zentgraf, Thomas and Kitzerow, Heinz-Siegfried}},
  journal      = {{Liquid Crystals}},
  number       = {{7-10}},
  pages        = {{1193--1203}},
  publisher    = {{Taylor & Francis}},
  title        = {{{Geometric-phase metalens to be used for tunable optical tweezers in microfluidics}}},
  doi          = {{10.1080/02678292.2023.2171146}},
  volume       = {{50}},
  year         = {{2023}},
}

@article{55900,
  author       = {{Scharwald, Dennis and Meier, Torsten and Sharapova, Polina}},
  issn         = {{2643-1564}},
  journal      = {{Physical Review Research}},
  number       = {{4}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Phase sensitivity of spatially broadband high-gain SU(1,1) interferometers}}},
  doi          = {{10.1103/physrevresearch.5.043158}},
  volume       = {{5}},
  year         = {{2023}},
}

@article{31059,
  abstract     = {{In this article we prove meromorphic continuation of weighted zeta functions in the framework of open hyperbolic systems by using the meromorphically continued restricted resolvent of Dyatlov and Guillarmou (2016). We obtain a residue formula proving equality between residues of weighted zetas and invariant Ruelle distributions. We combine this equality with results of Guillarmou, Hilgert and Weich (2021) in order to relate the residues to Patterson-Sullivan distributions. Finally we provide proof-of-principle results concerning the numerical calculation of invariant Ruelle distributions for 3-disc scattering systems.}},
  author       = {{Schütte, Philipp and Weich, Tobias and Barkhofen, Sonja}},
  journal      = {{Communications in Mathematical Physics}},
  pages        = {{655--678}},
  title        = {{{Meromorphic Continuation of Weighted Zeta Functions on Open Hyperbolic Systems}}},
  doi          = {{https://doi.org/10.1007/s00220-022-04538-z}},
  volume       = {{398}},
  year         = {{2023}},
}

@article{57677,
  abstract     = {{<jats:p>We present the fabrication of strain-free quantum dots in the In0.53Ga0.47As/In0.52Al0.48As-system lattice matched to InP, as future sources for single and entangled photons for long-haul fiber-based quantum communication in the optical C-band. We achieved these quantum dots by local droplet etching via InAl droplets in an In0.52Al0.48As layer and subsequent filling of the holes with In0.53Ga0.47As. Here, we present detailed investigations of the hole morphologies measured by atomic force microscopy. Statistical analysis of a set of nanoholes reveals a high degree of symmetry for nearly half of them when etched at optimized temperatures. Overgrowth with 50–150 nm In0.52Al0.48As increases their diameter and elongates the holes along the [01̄1]-direction. By systematically scanning the parameter space, we were able to fill the holes with In0.53Ga0.47As, and by capping the filled holes and performing photoluminescence measurements, we observe photoluminescence emission in the O-band up into the C-band depending on the filling height of the nanoholes.</jats:p>}},
  author       = {{Deutsch, Dennis and Buchholz, C. and Zolatanosha, V. and Jöns, K. D. and Reuter, Dirk}},
  issn         = {{2158-3226}},
  journal      = {{AIP Advances}},
  number       = {{5}},
  publisher    = {{AIP Publishing}},
  title        = {{{Telecom C-band photon emission from (In,Ga)As quantum dots generated by filling nanoholes in In0.52Al0.48As layers}}},
  doi          = {{10.1063/5.0147281}},
  volume       = {{13}},
  year         = {{2023}},
}

@inproceedings{45398,
  author       = {{Kulgemeyer, Christoph and Sterzing, Fabian Gabriel and Hörnlein, Madeleine}},
  editor       = {{Van Vorst, Helena}},
  location     = {{Aachen}},
  publisher    = {{Gesellschaft für Didaktik der Chemie und Physik (GDCP)}},
  title        = {{{Von der "Shallowing Hypothese" zur "Illusion of Understanding" -wie wirken Erklärvideos und Lehrbuchtexte auf Wissen und Verstehensillusion?}}},
  year         = {{2023}},
}

@inproceedings{45399,
  author       = {{Hörnlein, Madeleine and Kulgemeyer, Christoph}},
  editor       = {{Van Vorst, Helena}},
  location     = {{Aachen}},
  publisher    = {{Gesellschaft für Didaktik der Chemie und Physik (GDCP)}},
  title        = {{{"Aus Erklärvideos lernt man nur oberflächlich" - oder erwirbt man auch Konzeptwissen?}}},
  year         = {{2023}},
}

@inbook{45277,
  author       = {{Kulgemeyer, Christoph and Sterzing, Fabian Gabriel and Hörnlein, Madeleine}},
  booktitle    = {{Digital Physik unterrichten. Grundlagen, Impulse, Perspektiven}},
  editor       = {{Wilhelm, Thomas}},
  pages        = {{230--244}},
  publisher    = {{Klett Kallmeyer}},
  title        = {{{Aus Erklärvideos lernen}}},
  year         = {{2023}},
}

@inbook{60483,
  author       = {{Weiler, David Christoph and Burde, Jan-Philipp and Große-Heilmann, Rike Isabel and Lachner, Andreas and Riese, Josef and Schubatzky, Thomas}},
  booktitle    = {{Lehr-Lern-Labore und Digitalisierung}},
  pages        = {{47–62}},
  publisher    = {{Springer Fachmedien Wiesbaden}},
  title        = {{{Förderung von digitalisierungsbezogenen Kompetenzen von angehenden Physiklehrkräften mit dem SQD-Modell im Projekt DiKoLeP}}},
  doi          = {{10.1007/978-3-658-40109-2_4}},
  year         = {{2023}},
}

@article{61252,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>The biexciton‐exciton emission cascade commonly used in quantum‐dot systems to generate polarization entanglement yields photons with intrinsically limited indistinguishability. In the present work, it focuses on the generation of pairs of photons with high degrees of polarization entanglement and simultaneously high indistinguishability. It achieves this goal by selectively reducing the biexciton lifetime with an optical resonator. It demonstrates that a suitably tailored circular Bragg reflector fulfills the requirements of sufficient selective Purcell enhancement of biexciton emission paired with spectrally broad photon extraction and twofold degenerate optical modes. The in‐depth theoretical study combines (i) the optimization of realistic photonic structures solving Maxwell's equations from which model parameters are extracted as input for (ii) microscopic simulations of quantum‐dot cavity excitation dynamics with full access to photon properties. It reports non‐trivial dependencies on system parameters and use the predictive power of the combined theoretical approach to determine the optimal range of Purcell enhancement that maximizes indistinguishability and entanglement to near unity values, here specifically for the telecom C‐band at 1550 nm.</jats:p>}},
  author       = {{Bauch, David and Siebert, Dustin and Jöns, Klaus D. and Förstner, Jens and Schumacher, Stefan}},
  issn         = {{2511-9044}},
  journal      = {{Advanced Quantum Technologies}},
  number       = {{1}},
  publisher    = {{Wiley}},
  title        = {{{On‐Demand Indistinguishable and Entangled Photons Using Tailored Cavity Designs}}},
  doi          = {{10.1002/qute.202300142}},
  volume       = {{7}},
  year         = {{2023}},
}

@article{61266,
  abstract     = {{<jats:p>This review examines the use of continuous-variable spectroscopy techniques for investigating quantum coherence and light-matter interactions in semiconductor systems with ultrafast dynamics. Special emphasis is placed on multichannel homodyne detection as a powerful tool to measure the quantum coherence and the full density matrix of a polariton system. Observations, such as coherence times that exceed the nanosecond scale obtained by monitoring the temporal decay of quantum coherence in a polariton condensate, are discussed. Proof-of-concept experiments and numerical simulations that demonstrate the enhanced resourcefulness of the produced system states for modern quantum protocols are assessed. The combination of tailored resource quantifiers and ultrafast spectroscopy techniques that have recently been demonstrated paves the way for future applications of quantum information technologies.</jats:p>}},
  author       = {{Lüders, Carolin and Barkhausen, Franziska and Pukrop, Matthias and Rozas, Elena and Sperling, Jan and Schumacher, Stefan and Aßmann, Marc}},
  issn         = {{2159-3930}},
  journal      = {{Optical Materials Express}},
  number       = {{11}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Continuous-variable quantum optics and resource theory for ultrafast semiconductor spectroscopy [Invited]}}},
  doi          = {{10.1364/ome.497006}},
  volume       = {{13}},
  year         = {{2023}},
}

@article{61264,
  author       = {{Yu, Yueyang and Dong, Chuan-Ding and Binder, Rolf and Schumacher, Stefan and Ning, Cun-Zheng}},
  issn         = {{1936-0851}},
  journal      = {{ACS Nano}},
  number       = {{5}},
  pages        = {{4230--4238}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Strain-Induced Indirect-to-Direct Bandgap Transition, Photoluminescence Enhancement, and Linewidth Reduction in Bilayer MoTe<sub>2</sub>}}},
  doi          = {{10.1021/acsnano.2c01665}},
  volume       = {{17}},
  year         = {{2023}},
}

@article{61269,
  author       = {{Gao, Ying and Ma, Xuekai and Zhai, Xiaokun and Xing, Chunzi and Gao, Meini and Dai, Haitao and Wu, Hao and Liu, Tong and Ren, Yuan and Wang, Xiao and Pan, Anlian and Hu, Wei and Schumacher, Stefan and Gao, Tingge}},
  issn         = {{2469-9950}},
  journal      = {{Physical Review B}},
  number       = {{20}},
  publisher    = {{American Physical Society (APS)}},
  title        = {{{Single-shot spatial instability and electric control of polariton condensates at room temperature}}},
  doi          = {{10.1103/physrevb.108.205303}},
  volume       = {{108}},
  year         = {{2023}},
}

@article{61267,
  abstract     = {{<jats:p>Dynamics-induced interchain charge transfer in a polymer aggregate in stack configuration can be understood by single-oligomer polaron energy.</jats:p>}},
  author       = {{Bauch, Fabian and Dong, Chuan-Ding and Schumacher, Stefan}},
  issn         = {{2050-7526}},
  journal      = {{Journal of Materials Chemistry C}},
  number       = {{38}},
  pages        = {{12992--12998}},
  publisher    = {{Royal Society of Chemistry (RSC)}},
  title        = {{{Dynamics-induced charge transfer in semiconducting conjugated polymers}}},
  doi          = {{10.1039/d3tc02263c}},
  volume       = {{11}},
  year         = {{2023}},
}

@inproceedings{61362,
  abstract     = {{<jats:p>We study the interaction of gray tracking and DC ionic conductivity in Potassium Titanyl Phosphate (KTiOPO<jats:sub>4</jats:sub>, KTP) and present a novel way to reduce conductivity via a potassium nitrate treatment improving the device quality.</jats:p>}},
  author       = {{Eigner, Christof and Padberg, Laura and Quiring, Viktor and Bocchini, Adriana and Santandrea, Matteo and Gerstmann, Uwe and Schmidt, Wolf Gero and Silberhorn, Christine}},
  booktitle    = {{CLEO 2023}},
  publisher    = {{Optica Publishing Group}},
  title        = {{{Potassium Titanyl Phosphate Material Engineering Boosting Integrated Optical Source Performance}}},
  doi          = {{10.1364/cleo_at.2023.jw2a.57}},
  year         = {{2023}},
}

@inbook{61360,
  author       = {{Hajduk, Andreas and Zare Pour, Mohammad Amin and Paszuk, Agnieszka and Guidat, Margot and Löw, Mario and Ullmann, Fabian and Moritz, Dominik C. and Hofmann, Jan P. and Krischok, Stefan and Runge, Erich and Schmidt, Wolf Gero and Jaegermann, Wolfram and May, Matthias M. and Hannappel, Thomas}},
  booktitle    = {{Encyclopedia of Solid-Liquid Interfaces}},
  isbn         = {{9780323856706}},
  publisher    = {{Elsevier}},
  title        = {{{(Photo-)electrochemical reactions on semiconductor surfaces, part B: III-V surfaces–atomic and electronic structure}}},
  doi          = {{10.1016/b978-0-323-85669-0.00113-6}},
  year         = {{2023}},
}