TY - JOUR AB - Broadband coherent anti-Stokes Raman scattering (BCARS) is a powerful spectroscopy method combining high signal intensity with spectral sensitivity, enabling rapid imaging of heterogeneous samples in biomedical research and, more recently, in crystalline materials. However, BCARS encounters spectral distortion due to a setup-dependent non-resonant background (NRB). This study assesses BCARS reproducibility through a round robin experiment using two distinct BCARS setups and crystalline materials with varying structural complexity, including diamond, 6H-SiC, KDP, and KTP. The analysis compares setup-specific NRB correction procedures, detected and NRB-removed spectra, and mode assignment. We determine the influence of BCARS setup parameters like pump wavelength, pulse width, and detection geometry and provide a practical guide for optimizing BCARS setups for solid-state applications. AU - Hempel, Franz AU - Vernuccio, Federico AU - König, Lukas AU - Buschbeck, Robin AU - Rüsing, Michael AU - Cerullo, Giulio AU - Polli, Dario AU - Eng, Lukas M. ID - 49652 IS - 1 JF - Applied Optics KW - Atomic and Molecular Physics KW - and Optics KW - Engineering (miscellaneous) KW - Electrical and Electronic Engineering SN - 1559-128X TI - Comparing transmission- and epi-BCARS: a round robin on solid-state materials VL - 63 ER - TY - JOUR AU - Heinisch, Nils AU - Köcher, Nikolas AU - Bauch, David AU - Schumacher, Stefan ID - 50829 IS - 1 JF - Physical Review Research SN - 2643-1564 TI - Swing-up dynamics in quantum emitter cavity systems: Near ideal single photons and entangled photon pairs VL - 6 ER - TY - JOUR AB - Superconducting nanowire single-photon detectors (SNSPDs) have been widely used to study the discrete nature of quantum states of light in the form of photon-counting experiments. We show that SNSPDs can also be used to study continuous variables of optical quantum states by performing homodyne detection at a bandwidth of 400 kHz. By measuring the interference of a continuous-wave field of a local oscillator with the field of the vacuum state using two SNSPDs, we show that the variance of the difference in count rates is linearly proportional to the photon flux of the local oscillator over almost five orders of magnitude. The resulting shot-noise clearance of (46.0 ± 1.1) dB is the highest reported clearance for a balanced optical homodyne detector, demonstrating their potential for measuring highly squeezed states in the continuous-wave regime. In addition, we measured a CMRR = 22.4 dB. From the joint click counting statistics, we also measure the phase-dependent quadrature of a weak coherent state to demonstrate our device’s functionality as a homodyne detector. AU - Protte, Maximilian AU - Schapeler, Timon AU - Sperling, Jan AU - Bartley, Tim ID - 50840 IS - 1 JF - Optica Quantum SN - 2837-6714 TI - Low-noise balanced homodyne detection with superconducting nanowire single-photon detectors VL - 2 ER - TY - JOUR AU - Wingenbach, Jan AU - Schumacher, Stefan AU - Ma, Xuekai ID - 51105 JF - Physical Review Research, in press TI - Manipulating spectral topology and exceptional points by nonlinearity in non-Hermitian polariton systems ER - TY - JOUR AU - Liang, Qian AU - Ma, Xuekai AU - Gu, Chunling AU - Ren, Jiahuan AU - An, Cunbin AU - Fu, Hongbing AU - Schumacher, Stefan AU - Liao, Qing ID - 51104 JF - Journal of the American Chemical Society (JACS) TI - Photochemical Reaction Enabling the Engineering of Photonic Spin−Orbit Coupling in Organic-Crystal Optical Microcavities ER - TY - JOUR AU - Schneider, Tobias AU - Gao, Wenlong AU - Zentgraf, Thomas AU - Schumacher, Stefan AU - Ma, Xuekai ID - 51106 JF - Nanophotonics TI - Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates ER - TY - JOUR AB - Ferroelectric domain wall (DW) conductivity (DWC) can be attributed to two separate mechanisms: (a) the injection/ejection of charge carriers across the Schottky barrier formed at the (metal-)electrode-DW junction and (b) the transport of those charge carriers along the DW. Current-voltage (I-U) characteristics, recorded at variable temperatures from LiNbO3 (LNO) DWs, are clearly able to differentiate between these two contributions. Practically, they allow us to directly quantify the physical parameters relevant to the two mechanisms (a) and (b) mentioned above. These are, for example, the resistance of the DW, the saturation current, the ideality factor, and the Schottky barrier height of the electrode-DW junction. Furthermore, the activation energies needed to initiate the thermally activated electronic transport along the DWs can be extracted. In addition, we show that electronic transport along LNO DWs can be elegantly viewed and interpreted in an adapted semiconductor picture based on a double-diode, double-resistor equivalent-circuit model, the R2D2 model. Finally, our R2D2 model was checked for its universality by successfully fitting the I-U curves of not only z-cut LNO bulk DWs, but equally of z-cut thin-film LNO DWs, and of x-cut thin-film DWs as reported in literature. AU - Zahn, Manuel AU - Beyreuther, Elke AU - Kiseleva, Iuliia AU - Lotfy, Ahmed Samir AU - McCluskey, Conor J. AU - Maguire, Jesi R. AU - Suna, Ahmet AU - Rüsing, Michael AU - Gregg, J. Marty AU - Eng, Lukas M. ID - 51156 IS - 2 JF - Physical Review Applied KW - General Physics and Astronomy SN - 2331-7019 TI - Equivalent-circuit model that quantitatively describes domain-wall conductivity in ferroelectric lithium VL - 21 ER - TY - JOUR AB - Charge transfer mechanism in the deprotonation-induced n-type doping of PCBM. AU - Dong, Chuan-Ding AU - Bauch, Fabian AU - Hu, Yuanyuan AU - Schumacher, Stefan ID - 51221 IS - 5 JF - Physical Chemistry Chemical Physics KW - Physical and Theoretical Chemistry KW - General Physics and Astronomy SN - 1463-9076 TI - Charge transfer in superbase n-type doping of PCBM induced by deprotonation VL - 26 ER - TY - BOOK ED - Blumberg, Eva ED - Niederhaus, Constanze ED - Mischendahl, Anne ID - 40014 TI - Mehrsprachigkeit in der Schule. Sprachbildung im und durch Sachunterricht. ER - TY - JOUR AU - Babai-Hemati, Jonas AU - vom Bruch, Felix AU - Herrmann, Harald AU - Silberhorn, Christine ID - 51339 JF - Optics Express KW - Atomic and Molecular Physics KW - and Optics SN - 1094-4087 TI - Tailored second harmonic generation inTi-diffused PPLN waveguides usingmicro-heaters ER - TY - JOUR AU - Cui, Tie Jun AU - Zhang, Shuang AU - Alu, Andrea AU - Wegener, Martin AU - Pendry, John AU - Luo, Jie AU - Lai, Yun AU - Wang, Zuojia AU - Lin, Xiao AU - Chen, Hongsheng AU - Chen, Ping AU - Wu, Rui-Xin AU - Yin, Yuhang AU - Zhao, Pengfei AU - Chen, Huanyang AU - Li, Yue AU - Zhou, Ziheng AU - Engheta, Nader AU - Asadchy, V. S. AU - Simovski, Constantin AU - Tretyakov, Sergei A AU - Yang, Biao AU - Campbell, Sawyer D. AU - Hao, Yang AU - Werner, Douglas H AU - Sun, Shulin AU - Zhou, Lei AU - Xu, Su AU - Sun, Hong-Bo AU - Zhou, Zhou AU - Li, Zile AU - Zheng, Guoxing AU - Chen, Xianzhong AU - Li, Tao AU - Zhu, Shi-Ning AU - Zhou, Junxiao AU - Zhao, Junxiang AU - Liu, Zhaowei AU - Zhang, Yuchao AU - Zhang, Qiming AU - Gu, Min AU - Xiao, Shumin AU - Liu, Yongmin AU - Zhang, Xiaoyu AU - Tang, Yutao AU - Li, Guixin AU - Zentgraf, Thomas AU - Koshelev, Kirill AU - Kivshar, Yuri S. AU - Li, Xin AU - Badloe, Trevon AU - Huang, Lingling AU - Rho, Junsuk AU - Wang, Shuming AU - Tsai, Din Ping AU - Bykov, A. Yu. AU - Krasavin, Alexey V AU - Zayats, Anatoly V AU - McDonnell, Cormac AU - Ellenbogen, Tal AU - Luo, Xiangang AU - Pu, Mingbo AU - Garcia-Vidal, Francisco J AU - Liu, Liangliang AU - Li, Zhuo AU - Tang, Wenxuan AU - Ma, Hui Feng AU - Zhang, Jingjing AU - Luo, Yu AU - Zhang, Xuanru AU - Zhang, Hao Chi AU - He, Pei Hang AU - Zhang, Le Peng AU - Wan, Xiang AU - Wu, Haotian AU - Liu, Shuo AU - Jiang, Wei Xiang AU - Zhang, Xin Ge AU - Qiu, Chengwei AU - Ma, Qian AU - Liu, Che AU - Li, Long AU - Han, Jiaqi AU - Li, Lianlin AU - Cotrufo, Michele AU - Caloz, Christophe AU - Deck-Léger, Z.-L. AU - Bahrami, A. AU - Céspedes, O. AU - Galiffi, Emanuele AU - Huidobro, P. A. AU - Cheng, Qiang AU - Dai, Jun Yan AU - Ke, Jun Cheng AU - Zhang, Lei AU - Galdi, Vincenzo AU - Di Renzo, Marco ID - 51519 JF - Journal of Physics: Photonics KW - Electrical and Electronic Engineering KW - Atomic and Molecular Physics KW - and Optics KW - Electronic KW - Optical and Magnetic Materials SN - 2515-7647 TI - Roadmap on electromagnetic metamaterials and metasurfaces ER - TY - JOUR AU - Zietlow, Christian AU - Lindner, Jörg ID - 52090 JF - Numerical Algorithms TI - ADMM-TGV image restoration for scientific applications with unbiased parameter choice ER - TY - JOUR AU - Bauch, Fabian AU - Dong, Chuan-Ding AU - Schumacher, Stefan ID - 52534 IS - 8 JF - The Journal of Physical Chemistry C KW - Surfaces KW - Coatings and Films KW - Physical and Theoretical Chemistry KW - General Energy KW - Electronic KW - Optical and Magnetic Materials SN - 1932-7447 TI - Dynamics of Electron–Hole Coulomb Attractive Energy and Dipole Moment of Hot Excitons in Donor–Acceptor Polymers VL - 128 ER - TY - JOUR AB - Miller's rule is an empirical relation between the nonlinear and linear optical coefficients that applies to a large class of materials but has only been rigorously derived for the classical Lorentz model with a weak anharmonic perturbation. In this work, we extend the proof and present a detailed derivation of Miller's rule for an equivalent quantum-mechanical anharmonic oscillator. For this purpose, the classical concept of velocity-dependent damping inherent to the Lorentz model is replaced by an adiabatic switch-on of the external electric field, which allows a unified treatment of the classical and quantum-mechanical systems using identical potentials and fields. Although the dynamics of the resulting charge oscillations, and hence the induced polarizations, deviate due to the finite zero-point motion in the quantum-mechanical framework, we find that Miller's rule is nevertheless identical in both cases up to terms of first order in the anharmonicity. With a view to practical applications, especially in the context of ab initio calculations for the optical response where adiabatically switched-on fields are widely assumed, we demonstrate that a correct treatment of finite broadening parameters is essential to avoid spurious errors that may falsely suggest a violation of Miller's rule, and we illustrate this point by means of a numerical example. AU - Meyer, Maximilian Tim AU - Schindlmayr, Arno ID - 52723 JF - Journal of Physics B: Atomic, Molecular and Optical Physics SN - 0953-4075 TI - Derivation of Miller's rule for the nonlinear optical susceptibility of a quantum anharmonic oscillator ER - TY - JOUR AU - Arends, Christian AU - Wolf, Lasse Lennart AU - Meinecke, Jasmin AU - Barkhofen, Sonja AU - Weich, Tobias AU - Bartley, Tim ID - 52876 IS - 1 JF - Physical Review Research KW - General Physics and Astronomy SN - 2643-1564 TI - Decomposing large unitaries into multimode devices of arbitrary size VL - 6 ER - TY - JOUR AB - Superconducting nanowire single-photon detectors (SNSPDs) show near unity efficiency, low dark count rate, and short recovery time. Combining these characteristics with temporal control of SNSPDs broadens their applications as in active de-latching for higher dynamic range counting or temporal filtering for pump-probe spectroscopy or LiDAR. To that end, we demonstrate active gating of an SNSPD with a minimum off-to-on rise time of 2.4 ns and a total gate length of 5.0 ns. We show how the rise time depends on the inductance of the detector in combination with the control electronics. The gate window is demonstrated to be fully and freely, electrically tunable up to 500 ns at a repetition rate of 1.0 MHz, as well as ungated, free-running operation. Control electronics to generate the gating are mounted on the 2.3 K stage of a closed-cycle sorption cryostat, while the detector is operated on the cold stage at 0.8 K. We show that the efficiency and timing jitter of the detector is not altered during the on-time of the gating window. We exploit gated operation to demonstrate a method to increase in the photon counting dynamic range by a factor 11.2, as well as temporal filtering of a strong pump in an emulated pump-probe experiment. AU - Hummel, Thomas AU - Widhalm, Alex AU - Höpker, Jan Philipp AU - Jöns, Klaus AU - Chang, Jin AU - Fognini, Andreas AU - Steinhauer, Stephan AU - Zwiller, Val AU - Zrenner, Artur AU - Bartley, Tim ID - 36471 IS - 1 JF - Optics Express KW - Atomic and Molecular Physics KW - and Optics SN - 1094-4087 TI - Nanosecond gating of superconducting nanowire single-photon detectors using cryogenic bias circuitry VL - 31 ER - TY - CONF AU - Hoya, Fabian Karl AU - Schulze, Jan Roland AU - Blumberg, Eva AU - Hellmich, Frank ID - 35892 TI - Effekte des Feedbacks von Lehrkräften auf die Selbstwirksamkeitsüberzeugungen und die intrinsische Motivation von Kindern im naturwissenschaftlichen Sachunterricht der Grundschule. Vortrag auf der 10. Tagung der Gesellschaft für Empirische Bildungsforschung (GEBF). Thema: „Bildung zwischen Unsicherheit und Evidenz“ ER - TY - THES AB - Für den Erwerb fachmethodischer Fähigkeiten stellen Laborpraktika eine zentrale Lerngelegenheiten des Physikstudiums dar. Trotz ihrer hohen Bedeutung fehlt ein hochschulfachdidaktischer Diskurs zu einer lehr-lerntheoretischen Fundierung. Zudem wird ihre Lernwirksamkeit aufgrund der bestehenden didaktischen Gestaltung kritisiert. Die weit verbreiteten engmaschigen Aufgabenstellungen enthalten keine Anreize zur tiefergehenden Auseinandersetzung mit den Inhalten. Um der Diskrepanz zwischen den Zielsetzungen und den von den Lernenden erworbenen Fähigkeiten entgegenzuwirken, liegen aktuell nur wenige und zudem nur punktuelle Grundlagen für eine evidenzbasierte Überarbeitung dieses Veranstaltungsformates vor. Ziel dieser Arbeit ist daher, einen Vorschlag für ein performanzorientiertes Kompetenzstrukturmodell auf universitärem Niveau zu entwickeln, das die Inhaltsbereiche, die experimentellen Fähigkeiten und Fertigkeiten sowie die Qualitätsausprägungen experimenteller Handlungen systematisiert.Die Modellierung ist auf Basis der Analyse videografierter experimenteller Performanz von 16 unterschiedlich fähigen Proband:innen realisiert worden. Für die Entwicklung der Dimensionen Fachmethodik und Qualitätsausprägung werden unter Nutzung der qualitativen Forschungsansätze Dokumentarische Methode und Typenbildung die charakteristischen Merkmale universitären Experimentierens identifiziert und anschließend systematisiert. Zur Prüfung der Passung des Modells zur Perspektive der Wissenschaft Physik ist ein Interrating mit einem Fachwissenschaftler durchgeführt worden, das sehr gute Übereinstimmungswerte liefert. Die Passung des Modells zur Perspektive der Praktikumsleiter:innen ist durch ein Expertenrating erfolgt. Ein Rangfolgen-Vergleich zeigt hohe Übereinstimmungswerte. AU - Bauer, Anna Brigitte ID - 37645 TI - Experimentelle Kompetenz Physikstudierender ER - TY - CHAP AU - Schröer, Franz AU - Tenberge, Claudia ED - Gill, David ED - Irving-Bell, Dawne ED - McLain, Matt ED - Wooff, David ID - 37641 KW - Curriculum KW - Inclusion KW - Sachunterricht KW - Participation SN - 9781350238411 T2 - Bloomsbury Handbook of Technology Education TI - Including: Thinking Towards an Inclusive Curriculum for Technology Education in German Primary Schools ER - TY - JOUR AU - Janicki, Nicole AU - Tenberge, Claudia ID - 39976 JF - Australasian Journal of Technology Education KW - technology education KW - teacher professionalisation KW - Computational Thinking KW - digitalization KW - learning robots TI - Technology education in elementary school using the example of 'learning robots' – development and evaluation of an in-service teacher training concept ER - TY - CONF AU - Schmidt, Rebekka AU - Tenberge, Claudia AU - Häsel-Weide, Uta ED - Vöing, Nerea ED - Schmidt, Rebekka ED - Neiske, Iris ID - 40520 TI - Lehre in Zeiten von Digitalisierung und Inklusion – Beispiele aus drei Fächern. ER - TY - JOUR AU - Sharapova, Polina R. AU - Kruk, Sergey S. AU - Solntsev, Alexander S. ID - 41035 JF - Laser & Photonics Reviews KW - Condensed Matter Physics KW - Atomic and Molecular Physics KW - and Optics KW - Electronic KW - Optical and Magnetic Materials SN - 1863-8880 TI - Nonlinear Dielectric Nanoresonators and Metasurfaces: Toward Efficient Generation of Entangled Photons ER - TY - GEN AB - Long-range quantum communication requires the development of in-out light-matter interfaces to achieve a quantum advantage in entanglement distribution. Ideally, these quantum interconnections should be as fast as possible to achieve high-rate entangled qubits distribution. Here, we demonstrate the coherent quanta exchange between single photons generated on-demand from a GaAs quantum dot and atomic ensemble in a $^{87}$Rb vapor quantum memory. Through an open quantum system analysis, we demonstrate the mapping between the quantized electric field of photons and the coherence of the atomic ensemble. Our results play a pivotal role in understanding quantum light-matter interactions at the short time scales required to build fast hybrid quantum networks. AU - Cui, Guo-Dong AU - Schweickert, Lucas AU - Jöns, Klaus D. AU - Namazi, Mehdi AU - Lettner, Thomas AU - Zeuner, Katharina D. AU - Montaña, Lara Scavuzzo AU - Silva, Saimon Filipe Covre da AU - Reindl, Marcus AU - Huang, Huiying AU - Trotta, Rinaldo AU - Rastelli, Armando AU - Zwiller, Val AU - Figueroa, Eden ID - 42049 T2 - arXiv:2301.10326 TI - Coherent Quantum Interconnection between On-Demand Quantum Dot Single Photons and a Resonant Atomic Quantum Memory ER - TY - JOUR AU - Lüders, Carolin AU - Gil-Lopez, Jano AU - Allgaier, Markus AU - Brecht, Benjamin AU - Aßmann, Marc AU - Silberhorn, Christine AU - Bayer, Manfred ID - 42158 IS - 1 JF - Physical Review Applied KW - General Physics and Astronomy SN - 2331-7019 TI - Tailored Frequency Conversion Makes Infrared Light Visible for Streak Cameras VL - 19 ER - TY - JOUR AU - Liang, Qian AU - Ma, Xuekai AU - Long, Teng AU - Yao, Jiannian AU - Liao, Qing AU - Fu, Hongbing ID - 35077 IS - 9 JF - Angewandte Chemie International Edition KW - General Chemistry KW - Catalysis SN - 1433-7851 TI - Circularly Polarized Lasing from a Microcavity Filled with Achiral Single‐Crystalline Microribbons VL - 62 ER - TY - JOUR AB - In real photonic quantum systems losses are an unavoidable factor limiting the scalability to many modes and particles, restraining their application in fields as quantum information and communication. For this reason, a considerable amount of engineering effort has been taken in order to improve the quality of particle sources and system components. At the same time, data analysis and collection methods based on post-selection have been used to mitigate the effect of particle losses. This has allowed for investigating experimentally multi-particle evolutions where the observer lacks knowledge about the system's intermediate propagation states. Nonetheless, the fundamental question how losses affect the behaviour of the surviving subset of a multi-particle system has not been investigated so far. For this reason, here we study the impact of particle losses in a quantum walk of two photons reconstructing the output probability distributions for one photon conditioned on the loss of the other in a known mode and temporal step of our evolution network. We present the underlying theoretical scheme that we have devised in order to model controlled particle losses, we describe an experimental platform capable of implementing our theory in a time multiplexing encoding. In the end we show how localized particle losses change the output distributions without altering their asymptotic spreading properties. Finally we devise a quantum civilization problem, a two walker generalisation of single particle recurrence processes. AU - Pegoraro, Federico AU - Held, Philip AU - Barkhofen, Sonja AU - Brecht, Benjamin AU - Silberhorn, Christine ID - 42648 IS - 3 JF - Physica Scripta SN - 0031-8949 TI - Dynamic conditioning of two particle discrete-time quantum walks VL - 98 ER - TY - JOUR AB - The achievement of a flat metasurface has realized extraordinary control over light–matter interaction at the nanoscale, enabling widespread use in imaging, holography, and biophotonics. However, three-dimensional metasurfaces with the potential to provide additional light–matter manipulation flexibility attract only little interest. Here, we demonstrate a three-dimensional metasurface scheme capable of providing dual phase control through out-of-plane plasmonic resonance of L-shape antennas. Under circularly polarized excitation at a specific wavelength, the L-shape antennas with rotating orientation angle act as spatially variant three-dimensional tilted dipoles and are able to generate desire phase delay for different polarization components. Generalized Snell's law is achieved for both in-plane and out-of-plane dipole components through arranging such L-shape antennas into arrays. These three-dimensional metasurfaces suggest a route for wavefront modulation and a variety of nanophotonic applications. AU - Li, Tianyou AU - Chen, Yanjie AU - Wang, Yongtian AU - Zentgraf, Thomas AU - Huang, Lingling ID - 43421 IS - 14 JF - Applied Physics Letters KW - Physics and Astronomy (miscellaneous) SN - 0003-6951 TI - Three-dimensional dipole momentum analog based on L-shape metasurface VL - 122 ER - TY - JOUR AU - De, Jianbo AU - Ma, Xuekai AU - Yin, Fan AU - Ren, Jiahuan AU - Yao, Jiannian AU - Schumacher, Stefan AU - Liao, Qing AU - Fu, Hongbing AU - Malpuech, Guillaume AU - Solnyshkov, Dmitry ID - 36416 IS - 3 JF - Journal of the American Chemical Society (JACS) KW - Colloid and Surface Chemistry KW - Biochemistry KW - General Chemistry KW - Catalysis SN - 0002-7863 TI - Room-Temperature Electrical Field-Enhanced Ultrafast Switch in Organic Microcavity Polariton Condensates VL - 145 ER - TY - JOUR AU - Jia, Jichao AU - Cao, Xue AU - Ma, Xuekai AU - De, Jianbo AU - Yao, Jiannian AU - Schumacher, Stefan AU - Liao, Qing AU - Fu, Hongbing ID - 35160 IS - 1 JF - Nature Communications KW - General Physics and Astronomy KW - General Biochemistry KW - Genetics and Molecular Biology KW - General Chemistry KW - Multidisciplinary SN - 2041-1723 TI - Circularly polarized electroluminescence from a single-crystal organic microcavity light-emitting diode based on photonic spin-orbit interactions VL - 14 ER - TY - JOUR AU - Rose, Hendrik AU - Vasil'ev, A. N. AU - Tikhonova, O. V. AU - Meier, Torsten AU - Sharapova, Polina ID - 37280 IS - 1 JF - Physical Review A SN - 2469-9926 TI - Quantum-optical excitations of semiconductor nanostructures in a microcavity using a two-band model and a single-mode quantum field VL - 107 ER - TY - JOUR AU - Cara, Eleonora AU - Hönicke, Philipp AU - Kayser, Yves AU - Lindner, Jörg K. N. AU - Castellino, Micaela AU - Murataj, Irdi AU - Porro, Samuele AU - Angelini, Angelo AU - De Leo, Natascia AU - Pirri, Candido Fabrizio AU - Beckhoff, Burkhard AU - Boarino, Luca AU - Ferrarese Lupi, Federico ID - 42953 IS - 3 JF - ACS Applied Polymer Materials KW - Organic Chemistry KW - Polymers and Plastics KW - Process Chemistry and Technology SN - 2637-6105 TI - Developing Quantitative Nondestructive Characterization of Nanomaterials: A Case Study on Sequential Infiltration Synthesis of Block Copolymers VL - 5 ER - TY - JOUR AU - Serino, Laura AU - Gil López, Jano AU - Stefszky, Michael AU - Ricken, Raimund AU - Eigner, Christof AU - Brecht, Benjamin AU - Silberhorn, Christine ID - 44081 IS - 2 JF - PRX Quantum KW - General Physics and Astronomy KW - Mathematical Physics KW - Applied Mathematics KW - Electronic KW - Optical and Magnetic Materials KW - Electrical and Electronic Engineering KW - General Computer Science SN - 2691-3399 TI - Realization of a Multi-Output Quantum Pulse Gate for Decoding High-Dimensional Temporal Modes of Single-Photon States VL - 4 ER - TY - CONF AB - The nonlinear optical response of quantum well excitons is investigated experimentally using polarization resolved four wave mixing, optical-pump optical-probe, and optical-pump Terahertz-probe spectroscopy. The four-wave mixing data reveal clear signatures of coherent biexcitons which concur with straight-forward polarization selection rules at the Γ point. The type-I samples show the well-established time-domain beating signatures in the transients as well as the corresponding spectral signatures clearly. The latter are also present in type-II samples; however, the smaller exciton and biexciton binding energies in these structures infer longer beating times which, in turn, are accompanied by faster dephasing of the type-II exciton coherences. Furthermore, the THz absorption following spectrally narrow, picosecond excitation at energies in the vicinity of the 1s exciton resonance are discussed. Here, the optical signatures yield the well-established redshifts and blueshifts for the appropriate polarization geometries in type-I quantum well samples also termed “AC Stark Effect”. The THz probe reveals intriguing spectral features which can be ascribed to coherent negative absorption following an excitation into a virtual state for an excitation below the 1s exciton resonance. Furthermore, the scattering and ionization of excitons is discussed for several excitation geometries yielding control rules for elastic and inelastic quasiparticle collisions. AU - Meier, Torsten AU - Stein, M. AU - Schäfer, F. AU - Anders, D. AU - Littmann, J. H. AU - Fey, M. AU - Trautmann, Alexander AU - Ngo, C. AU - Steiner, J. T. AU - Reichelt, Matthias AU - Fuchs, C. AU - Volz, K. AU - Chatterjee, S. ID - 43189 T2 - Ultrafast Phenomena and Nanophotonics XXVII TI - Experimental studies of the excitonic nonlinear response of GaAs-based type-I and type-II quantum well structures interacting with optical and terahertz fields VL - 12419 ER - TY - CONF AB - Anomalous currents refer to electronic currents that flow perpendicularly to the direction of the accelerating electric field. Such anomalous currents can be generated when Terahertz fields are applied after an optical interband excitation of GaAs quantum wells. The underlying processes are investigated by numerical solutions of the semiconductor Bloch equations in the length gauge. Excitonic effects are included by treating the manybody Coulomb interaction in time-dependent Hartree-Fock approximation and additionally also carrier-phonon scattering processes are considered. The band structure and matrix elements are obtained from a 14-band k · p model within the envelope function approximation. The random phase factors of the matrix elements that appear due to the separate numerical diagonalization at each k-point are treated by applying a smooth gauge transformation. We present the macroscopic Berry curvature and anomalous current transients with and without excitonic effects. It is demonstrated that the resonant optical excitation of excitonic resonances can significantly enhance the Berry curvature and the anomalous currents. AU - Meier, Torsten AU - Ngo, C. AU - Priyadarshi, S. AU - Duc, H. T. AU - Bieler, M. ID - 43191 T2 - Ultrafast Phenomena and Nanophotonics XXVII TI - Terahertz-induced anomalous currents following the optical excitation of excitons in semiconductor quantum wells VL - 12419 ER - TY - CONF AB - The nonlinear optical response of quantum well excitons excited by optical fields is analyzed by numerical solutions of the semiconductor Bloch equations. Differential absorption spectra are computed for resonant pumping at the exciton resonance and the dependence of the absorption changes on the polarization directions of the pump and probe pulses is investigated. Coherent biexcitonic many-body correlations are included in our approach up to third-order in the optical fields. Results are presented for spatially-direct type-I and spatiallyindirect type-II quantum well systems. Due to the spatial inhomogeneity, in type-II structures a finite coupling between excitons of opposite spins exists already on the Hartree-Fock level and contributes to the absorption changes for the case of opposite circularly polarized pump and probe pulses. AU - Meier, Torsten AU - Trautmann, Alexander AU - Stein, M. AU - Schäfer, F. AU - Anders, D. AU - Ngo, C. AU - Steiner, J. T. AU - Reichelt, Matthias AU - Chatterjee, S. ID - 43190 T2 - Ultrafast Phenomena and Nanophotonics XXVII TI - Analysis of the nonlinear optical response of excitons in type-I and type-II quantum wells including many-body correlations VL - 12419 ER - TY - JOUR AU - Meier, Torsten AU - Schäfer, F. AU - Stein, M. AU - Lorenz, J. AU - Dobener, F. AU - Ngo, C. AU - Steiner, J. T. AU - Fuchs, C. AU - Stolz, W. AU - Volz, K. AU - Hader, J. AU - Moloney, J.V. AU - Koch, S.W. AU - Chatterjee, S. ID - 43139 IS - 8 JF - Applied Physics Letters TI - Gain recovery dynamics in active type-II semiconductor heterostructures VL - 122 ER - TY - GEN AU - Meier, Torsten AU - Grisard, S. AU - Trifonov, A.V. AU - Rose, Hendrik AU - Reichhardt, R. AU - Reichelt, Matthias AU - Schneider, C. AU - Kamp, M. AU - Höfling, S. AU - Bayer, M. AU - Akimov, I.A ID - 43132 T2 - arxiv:2302.02480 TI - Temporal sorting of optical multi-wave-mixing processes in semiconductor quantum dots ER - TY - JOUR AU - Sperling, Jan AU - Agudelo, Elizabeth ID - 44050 IS - 4 JF - Physical Review A SN - 2469-9926 TI - Entanglement of particles versus entanglement of fields: Independent quantum resources VL - 107 ER - TY - JOUR AU - Sperling, Jan AU - Gianani, Ilaria AU - Barbieri, Marco AU - Agudelo, Elizabeth ID - 40477 IS - 1 JF - Physical Review A SN - 2469-9926 TI - Detector entanglement: Quasidistributions for Bell-state measurements VL - 107 ER - TY - JOUR AU - Lüders, Carolin AU - Pukrop, Matthias AU - Barkhausen, Franziska AU - Rozas, Elena AU - Schneider, Christian AU - Höfling, Sven AU - Sperling, Jan AU - Schumacher, Stefan AU - Aßmann, Marc ID - 42973 IS - 11 JF - Physical Review Letters KW - General Physics and Astronomy SN - 0031-9007 TI - Tracking Quantum Coherence in Polariton Condensates with Time-Resolved Tomography VL - 130 ER - TY - BOOK AU - Bauer, Anna Brigitte ID - 44083 SN - 978-3-8325-5625-9 TI - Experimentelle Kompetenz Physikstudierender. Entwicklung und erste Erprobung eines performanzorientierten Kompetenzstrukturmodells unter Nutzung qualitativer Methoden VL - 352 ER - TY - JOUR AB - Dispersion is present in every optical setup and is often an undesired effect, especially in nonlinear-optical experiments where ultrashort laser pulses are needed. Typically, bulky pulse compressors consisting of gratings or prisms are used to address this issue by precompensating the dispersion of the optical components. However, these devices are only able to compensate for a part of the dispersion (second-order dispersion). Here, we present a compact pulse-shaping device that uses plasmonic metasurfaces to apply an arbitrarily designed spectral phase delay allowing for a full dispersion control. Furthermore, with specific phase encodings, this device can be used to temporally reshape the incident laser pulses into more complex pulse forms such as a double pulse. We verify the performance of our device by using an SHG-FROG measurement setup together with a retrieval algorithm to extract the dispersion that our device applies to an incident laser pulse. AU - Geromel, René AU - Georgi, Philip AU - Protte, Maximilian AU - Lei, Shiwei AU - Bartley, Tim AU - Huang, Lingling AU - Zentgraf, Thomas ID - 44044 IS - 8 JF - Nano Letters KW - Mechanical Engineering KW - Condensed Matter Physics KW - General Materials Science KW - General Chemistry KW - Bioengineering SN - 1530-6984 TI - Compact Metasurface-Based Optical Pulse-Shaping Device VL - 23 ER - TY - CHAP AU - Kulgemeyer, Christoph AU - Sterzing, Fabian AU - Hörnlein, Madeleine ED - Wilhelm, Thomas ID - 45277 T2 - Digital Physik unterrichten. Grundlagen, Impulse, Perspektiven TI - Aus Erklärvideos lernen ER - TY - CHAP AU - Weiler, David AU - Burde, Jan-Philipp AU - Große-Heilmann, Rike Isabel AU - Lachner, Andreas AU - Riese, Josef AU - Schubatzky, Thomas ED - Meier, Monique ED - Greefrath, Gilbert ED - Hammann, Marcus ED - Wodzinski, Rita ED - Ziepprecht, Kathrin ID - 45171 SN - 2524-8677 T2 - Lehr-Lern-Labore und Digitalisierung TI - Förderung von digitalisierungsbezogenen Kompetenzen von angehenden Physiklehrkräften mit dem SQD-Modell im Projekt DiKoLeP ER - TY - CONF AU - Kulgemeyer, Christoph AU - Sterzing, Fabian AU - Hörnlein, Madeleine ED - Van Vorst, Helena ID - 45398 TI - Von der "Shallowing Hypothese" zur "Illusion of Understanding" -wie wirken Erklärvideos und Lehrbuchtexte auf Wissen und Verstehensillusion? ER - TY - CONF AU - Hörnlein, Madeleine AU - Kulgemeyer, Christoph ED - Van Vorst, Helena ID - 45399 TI - "Aus Erklärvideos lernt man nur oberflächlich" - oder erwirbt man auch Konzeptwissen? ER - TY - JOUR AU - Kruse, Stephan AU - Serino, Laura AU - Folge, Patrick Fabian AU - Echeverria Oviedo, Dana AU - Bhattacharjee, Abhinandan AU - Stefszky, Michael AU - Scheytt, J. Christoph AU - Brecht, Benjamin AU - Silberhorn, Christine ID - 45485 IS - 14 JF - IEEE Photonics Technology Letters KW - Electrical and Electronic Engineering KW - Atomic and Molecular Physics KW - and Optics KW - Electronic KW - Optical and Magnetic Materials SN - 1041-1135 TI - A Pulsed Lidar System With Ultimate Quantum Range Accuracy VL - 35 ER - TY - CONF AU - Buschütter, David AU - Zeller, Jannis AU - Oltmanns, Stefan AU - Borowski, Andreas AU - Kulgemeyer, Christoph AU - Riese, Josef AU - Vogelsang, Christoph ED - van Vorst, Helena ID - 45567 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022 TI - Forschungsdatenmanagement erleichtern durch relationale Datenbanken: Ein Datenmodell für naturwissenschaftsdidaktische Forschung ER - TY - CONF AU - Zwick, Linda AU - Webersen, Yvonne AU - Wodzinski, Rita ED - van Vorst, Helena ID - 45576 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022 TI - Entwicklung von Schülervorstellungen zu NOS & NOSI im Physikunterricht ER - TY - CONF AU - Webersen, Yvonne ED - van Vorst, Helena ID - 45577 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022 TI - Entwicklung und Evaluation einer NdN-Unterrichtsreihe zur Unterstützung von Lernpfaden ER - TY - JOUR AB - AbstractBased on a literature review of studies on teachers’ professional competence and related assessment tools, this paper introduces a model of teacher education assessment. It is influenced by Miller’s (1990) framework of assessment in medical education and includes, among other aspects, performance assessments. This model is used to understand the potential effects of transferring assessment tools into a digital format with assessment feedback. Five examples for such a transfer will be discussed: three methods for various aspects of communication, a test for pedagogical content knowledge, and a test for content knowledge. All five are established instruments well-described in terms of validity. All five have recently been transferred into a digital format. The analysis of this transfer also reveals a potentially harmful effect of digital assessment. The closer an assessment instrument is to assessing action-related parts of professional competence, the more authenticity is required; however, digitisation tends to decrease this authenticity. This suggests that an increasing number of digital assessment tools in teacher education might result in an even more dominant focus on knowledge tests, ignoring other parts of professional competence. This article highlights the role of authenticity in validity and discusses the most suitable assessment format to address various parts of professional competence. It ends by highlighting the lessons learned from the transfer of assessment instruments into a digital format that other academic disciplines might find interesting. AU - Kulgemeyer, Christoph AU - Riese, Josef AU - Vogelsang, Christoph AU - Buschhüter, David AU - Borowski, Andreas AU - Weißbach, Anna AU - Jordans, Melanie AU - Reinhold, Peter AU - Schecker, Horst ID - 45562 JF - Zeitschrift für Erziehungswissenschaft KW - Education SN - 1434-663X TI - How authenticity impacts validity: Developing a model of teacher education assessment and exploring the effects of the digitisation of assessment methods Über Validität und Authentizität: Effekte des Transfers von Testinstrumenten in ein digitales Format auf die erhobenen Aspekte der professionellen Handlungskompetenz ER - TY - CONF AU - Große-Heilmann, Rike Isabel AU - Burde, Jan-Philipp AU - Riese, Josef AU - Schubatzky, Thomas AU - Weiler, David ED - van Vorst, Helena ID - 45563 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022 TI - Erwerb und Messung fachdidaktischen Wissens zum Einsatz digitaler Medien ER - TY - CONF AU - Jordans, Melanie AU - Riese, Josef ED - van Vorst, Helena ID - 45566 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022 TI - Unterrichtsplanung mit sinnvoller Einbettung digitaler Medien im PU ER - TY - CONF AU - Zeller, Jannis AU - Riese, Josef ED - van Vorst, Helena ID - 45565 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt Gesellschaft für Didaktik der Chemie und Physik Jahrestagung in Aachen 2022 TI - Datenbasierte Fähigkeitsprofile im Physikdidaktischen Wissen ER - TY - CONF AB - The nonlinear optical response of an ensemble of semiconductor quantum dots is analyzed by wave-mixing processes, where we focus on four-wave mixing with two incident pulses. Wave-mixing experiments are often described with semiclassical models, where the light is modeled classically and the material quantum mechanically. Here, however, we use a fully quantized model, where the light is given by a quantum state of light. Quantum light involves more degrees of freedom than classical light as e.g., its photon statistics and quantum correlations, which is a promising resource for quantum devices, such as quantum memories. The light-matter interaction is treated with a Jaynes-Cummings type model and the quantum field is given by a single mode since the quantum dots are embedded in a microcavity. We present numerical simulations of the four-wave-mixing response of a homogeneous system for pulse sequences and find a significant dependence of the result on the photon statistics of the incident pulses. The model constitutes a problem with a large state space which arises from the frequency distribution of the transition energies of the inhomogeneously broadened quantum dot ensemble that is coupled with a quantum light mode. Here we approximate the dynamics by summing over individual quantum dot-microcavity systems. Photon echoes arising from the excitation with different quantum states of light are simulated and compared. AU - Rose, Hendrik AU - Grisard, S. AU - Trifonov, A. V. AU - Reichhardt, R. AU - Reichelt, Matthias AU - Bayer, M. AU - Akimov, I. A. AU - Meier, Torsten ID - 43192 T2 - Ultrafast Phenomena and Nanophotonics XXVII TI - Theoretical analysis of four-wave mixing on semiconductor quantum dot ensembles with quantum light VL - 12419 ER - TY - JOUR AB - Since high-order harmonic generation (HHG) from atoms depends sensitively on the polarization of the driving laser field, the polarization gating (PG) technique was developed and applied successfully to generate isolated attosecond pulses from atomic gases. The situation is, however, different in solid-state systems as it has been demonstrated that due to collisions with neighboring atomic cores of the crystal lattice strong HHG can be generated even by elliptically- and circularly-polarized laser fields. Here we apply PG to solid-state systems and find that the conventional PG technique is inefficient for the generation of isolated ultrashort harmonic pulse bursts. In contrast, we demonstrate that a polarization-skewed laser pulse is able to confine the harmonic emission to a time window of less than one-tenth of the laser cycle. This method provides a novel way to control HHG and to generate isolated attosecond pulses in solids. AU - Song, Xiaohong AU - Yang, Shidong AU - Wang, Guifang AU - Lin, Jianpeng AU - Wang, Liang AU - Meier, Torsten AU - Yang, Weifeng ID - 45704 IS - 12 JF - Optics Express KW - Atomic and Molecular Physics KW - and Optics SN - 1094-4087 TI - Control of the electron dynamics in solid-state high harmonic generation on ultrafast time scales by a polarization-skewed laser pulse VL - 31 ER - TY - JOUR AU - Zuo, Ruixin AU - Song, Xiaohong AU - Ben, Shuai AU - Meier, Torsten AU - Yang, Weifeng ID - 45703 IS - 2 JF - Physical Review Research KW - General Physics and Astronomy SN - 2643-1564 TI - Revealing the nonadiabatic tunneling dynamics in solid-state high harmonic generation VL - 5 ER - TY - JOUR AU - Belobo, D. Belobo AU - Meier, Torsten ID - 45709 JF - Results in Physics KW - General Physics and Astronomy SN - 2211-3797 TI - Manipulation of nonautonomous nonlinear wave solutions of the generalized coupled Gross–Pitaevskii equations with spin–orbit interaction and weak Raman couplings ER - TY - CONF AU - Abbas, Nilab AU - Bauer, Anna Brigitte AU - Reinhold, Peter ED - van Vorst, Helena ID - 45759 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt TI - PSΦ: Entwicklung von Unterstützungsmaßnahmen für Theoretische Physik ER - TY - CONF AU - Bauer, Anna Brigitte AU - Reinhold, Peter ED - van Vorst, Helena ID - 45758 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt TI - PSФ: Entwicklung einer abgestimmten Studieneingangsphase (Physik) ER - TY - JOUR AB - A series of new organic donor–π–acceptor dyes incorporating a diquat moiety as a novel electron-acceptor unit have been synthesized and characterized. The analytical data were supported by DFT calculations. These dyes were explored in the aerobic thiocyanation of indoles and pyrroles. Here they showed a high photocatalytic activity under visible light, giving isolated yields of up to 97 %. In addition, the photocatalytic activity of standalone diquat and methyl viologen through formation of an electron donor acceptor complex is presented. AU - Meier, Armin AU - Badalov, Sabuhi AU - Biktagirov, Timur AU - Schmidt, Wolf Gero AU - Wilhelm, René ID - 43827 IS - 22 JF - Chemistry – A European Journal KW - General Chemistry KW - Catalysis KW - Organic Chemistry SN - 0947-6539 TI - Diquat Based Dyes: A New Class of Photoredox Catalysts and Their Use in Aerobic Thiocyanation VL - 29 ER - TY - JOUR AB - Perfect vector vortex beams (PVVBs) have attracted considerable interest due to their peculiar optical features. PVVBs are typically generated through the superposition of perfect vortex beams, which suffer from the limited number of topological charges (TCs). Furthermore, dynamic control of PVVBs is desirable and has not been reported. We propose and experimentally demonstrate hybrid grafted perfect vector vortex beams (GPVVBs) and their dynamic control. Hybrid GPVVBs are generated through the superposition of grafted perfect vortex beams with a multifunctional metasurface. The generated hybrid GPVVBs possess spatially variant rates of polarization change due to the involvement of more TCs. Each hybrid GPVVB includes different GPVVBs in the same beam, adding more design flexibility. Moreover, these beams are dynamically controlled with a rotating half waveplate. The generated dynamic GPVVBs may find applications in the fields where dynamic control is in high demand, including optical encryption, dense data communication, and multiple particle manipulation. AU - Ahmed, Hammad AU - Ansari, Muhammad Afnan AU - Li, Yan AU - Zentgraf, Thomas AU - Mehmood, Muhammad Qasim AU - Chen, Xianzhong ID - 45868 IS - 1 JF - Nature Communications KW - General Physics and Astronomy KW - General Biochemistry KW - Genetics and Molecular Biology KW - General Chemistry KW - Multidisciplinary SN - 2041-1723 TI - Dynamic control of hybrid grafted perfect vector vortex beams VL - 14 ER - TY - JOUR AB - Interference between single photons is key for many quantum optics experiments and applications in quantum technologies, such as quantum communication or computation. It is advantageous to operate the systems at telecommunication wavelengths and to integrate the setups for these applications in order to improve stability, compactness and scalability. A new promising material platform for integrated quantum optics is lithium niobate on insulator (LNOI). Here, we realise Hong-Ou-Mandel (HOM) interference between telecom photons from an engineered parametric down-conversion source in an LNOI directional coupler. The coupler has been designed and fabricated in house and provides close to perfect balanced beam splitting. We obtain a raw HOM visibility of (93.5 ± 0.7) %, limited mainly by the source performance and in good agreement with off-chip measurements. This lays the foundation for more sophisticated quantum experiments in LNOI. AU - Babel, Silia AU - Bollmers, Laura AU - Massaro, Marcello AU - Luo, Kai Hong AU - Stefszky, Michael AU - Pegoraro, Federico AU - Held, Philip AU - Herrmann, Harald AU - Eigner, Christof AU - Brecht, Benjamin AU - Padberg, Laura AU - Silberhorn, Christine ID - 45850 IS - 14 JF - Optics Express KW - Atomic and Molecular Physics KW - and Optics SN - 1094-4087 TI - Demonstration of Hong-Ou-Mandel interference in an LNOI directional coupler VL - 31 ER - TY - JOUR AU - Bopp, Frederik AU - Schall, Johannes AU - Bart, Nikolai AU - Vögl, Florian AU - Cullip, Charlotte AU - Sbresny, Friedrich AU - Boos, Katarina AU - Thalacker, Christopher AU - Lienhart, Michelle AU - Rodt, Sven AU - Reuter, Dirk AU - Ludwig, Arne AU - Wieck, Andreas D. AU - Reitzenstein, Stephan AU - Müller, Kai AU - Finley, Jonathan J. ID - 46133 IS - 16 JF - Physical Review B SN - 2469-9950 TI - Coherent driving of direct and indirect excitons in a quantum dot molecule VL - 107 ER - TY - JOUR AU - Littmann, Mario AU - Reuter, Dirk AU - As, Donat Josef ID - 46132 IS - 7 JF - physica status solidi (b) KW - Condensed Matter Physics KW - Electronic KW - Optical and Magnetic Materials SN - 0370-1972 TI - Remote Epitaxy of Cubic Gallium Nitride on Graphene‐Covered 3C‐SiC Substrates by Plasma‐Assisted Molecular Beam Epitaxy VL - 260 ER - TY - JOUR AB - This work reports a fully guided setup for single-mode squeezing on integrated titanium-indiffused periodically poled nonlinear resonators. A continuous-wave laser beam is delivered and the squeezed field is collected by single-mode fibers; up to −3.17(9) dB of useful squeezing is available in fibers. To showcase the usefulness of such a fiber-coupled device, we applied the generated squeezed light in a fiber-based phase sensing experiment, showing a quantum enhancement in the signal-to-noise ratio of 0.35 dB. Moreover, our investigation of the effect of photorefraction on the cavity resonance condition suggests that it causes system instabilities at high powers. AU - Domeneguetti, Renato AU - Stefszky, Michael AU - Herrmann, Harald AU - Silberhorn, Christine AU - Andersen, Ulrik L. AU - Neergaard-Nielsen, Jonas S. AU - Gehring, Tobias ID - 46138 IS - 11 JF - Optics Letters KW - Atomic and Molecular Physics KW - and Optics SN - 0146-9592 TI - Fully guided and phase locked Ti:PPLN waveguide squeezing for applications in quantum sensing VL - 48 ER - TY - JOUR AB - Site-controlled Ga droplets on AlGaAs substrates are fabricated using area-selective deposition of Ga through apertures in a mask during molecular beam epitaxy (MBE). The Ga droplets can be crystallized into GaAs quantum dots using a crystallization step under As flux. In order to model the complex process, including the masked deposition of the droplets and a reduction of their number during a thermal annealing step, a multiscale kinetic Monte Carlo (mkMC) simulation of self-assembled Ga droplet formation on AlGaAs is expanded for area-selective deposition. The simulation has only two free model parameters: the activation energy for surface diffusion and the activation energy for thermal escape of adatoms from a droplet. Simulated droplet numbers within the opening of the aperture agree quantitatively with the experimental results down to the perfect site-control, with one droplet per aperture. However, the model parameters are different compared to those of the self-assembled droplet growth. We attribute this to the presence of the mask in close proximity to the surface, which modifies the local process temperature and the As background. This approach also explains the dependence of the model parameters on the size of the aperture. AU - Feddersen, Stefan AU - Zolatanosha, Viktoryia AU - Alshaikh, Ahmed AU - Reuter, Dirk AU - Heyn, Christian ID - 46278 IS - 3 JF - Nanomaterials KW - General Materials Science KW - General Chemical Engineering SN - 2079-4991 TI - Modeling of Masked Droplet Deposition for Site-Controlled Ga Droplets VL - 13 ER - TY - JOUR AU - Lange, Nina Amelie AU - Schapeler, Timon AU - Höpker, Jan Philipp AU - Protte, Maximilian AU - Bartley, Tim ID - 46468 IS - 2 JF - Physical Review A SN - 2469-9926 TI - Degenerate photons from a cryogenic spontaneous parametric down-conversion source VL - 108 ER - TY - CONF AB - We present a miniaturized pulse shaping device that creates an arbitrary dispersion through the interaction of multiple metasurfaces on less than 2 mm3 volume. For this, a metalens and a grating-metasurface between two silver mirrors are fabricated. The grating contains further phase information to achieve the device's pulse shaping functionality. AU - Geromel, René AU - Georgi, Philip AU - Protte, Maximilian AU - Bartley, Tim AU - Huang, Lingling AU - Zentgraf, Thomas ID - 46485 T2 - CLEO: Fundamental Science 2023 TI - Dispersion control with integrated plasmonic metasurfaces ER - TY - JOUR AB - 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. AU - Deutsch, D. AU - Buchholz, C. AU - Zolatanosha, V. AU - Jöns, K. D. AU - Reuter, D. ID - 44851 IS - 5 JF - AIP Advances KW - General Physics and Astronomy SN - 2158-3226 TI - Telecom C-band photon emission from (In,Ga)As quantum dots generated by filling nanoholes in In0.52Al0.48As layers VL - 13 ER - TY - CONF AU - Elsner, Julia AU - Tenberge, Claudia AU - Fechner, Sabine ED - van Vorst, Helena ID - 45371 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt TI - Videoanalyse des Modellierprozesses von Grundschüler*innen VL - 43 ER - TY - JOUR AU - Zscherp, Mario Fabian AU - Jentsch, Silas Aurel AU - Müller, Marius Johannes AU - Lider, Vitalii AU - Becker, Celina AU - Chen, Limei AU - Littmann, Mario AU - Meier, Falco AU - Beyer, Andreas AU - Hofmann, Detlev Michael AU - As, Donat Josef AU - Klar, Peter Jens AU - Volz, Kerstin AU - Chatterjee, Sangam AU - Schörmann, Jörg ID - 46741 IS - 33 JF - ACS Applied Materials & Interfaces KW - General Materials Science SN - 1944-8244 TI - Overcoming the Miscibility Gap of GaN/InN in MBE Growth of Cubic InxGa1–xN VL - 15 ER - TY - JOUR AU - Schubatzky, Thomas AU - Burde, Jan-Philipp AU - Große-Heilmann, Rike Isabel AU - Haagen-Schützenhöfer, Claudia AU - Riese, Josef AU - Weiler, David ID - 47085 JF - Computers & Education KW - Education KW - General Computer Science SN - 0360-1315 TI - Predicting the development of digital media PCK/TPACK: The role of PCK, motivation to use digital media, interest in and previous experience with digital media VL - 206 ER - TY - JOUR AU - Zhai, Xiaokun AU - Ma, Xuekai AU - Gao, Ying AU - Xing, Chunzi AU - Gao, Meini AU - Dai, Haitao AU - Wang, Xiao AU - Pan, Anlian AU - Schumacher, Stefan AU - Gao, Tingge ID - 40274 IS - 13 JF - Physical Review Letters TI - Electrically controlling vortices in a neutral exciton polariton condensate at room temperature VL - 131 ER - TY - GEN AB - In planar microcavities, the transverse-electric and transverse-magnetic (TE-TM) mode splitting of cavity photons arises due to their different penetration into the Bragg mirrors and can result in optical spin-orbit coupling (SOC). In this work, we find that in a liquid crystal (LC) microcavity filled with perovskite microplates, the pronounced TE-TM splitting gives rise to a strong SOC that leads to the spatial instability of microcavity polariton condensates under single-shot excitation. Spatially varying hole burning and mode competition occurs between polarization components leading to different condensate profiles from shot to shot. The single-shot polariton condensates become stable when the SOC vanishes as the TE and TM modes are spectrally well separated from each other, which can be achieved by application of an electric field to our LC microcavity with electrically tunable anisotropy. Our findings are well reproduced and traced back to their physical origin by our detailed numerical simulations. With the electrical manipulation our work reveals how the shot-to-shot spatial instability of spatial polariton profiles can be engineered in anisotropic microcavities at room temperature, which will benefit the development of stable polariton-based optoeletronic and light-emitting devices. AU - Gao, Ying AU - Ma, Xuekai AU - Zhai, Xiaokun AU - Xing, Chunzi AU - Gao, Meini AU - Dai, Haitao AU - Wu, Hao AU - Liu, Tong AU - Ren, Yuan AU - Wang, Xiao AU - Pan, Anlian AU - Hu, Wei AU - Schumacher, Stefan AU - Gao, Tingge ID - 47532 T2 - arXiv:2305.01368 TI - Single-shot spatial instability and electric control of polariton condensates at room temperature ER - TY - GEN AB - 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. AU - Liang, Qian AU - Ma, Xuekai AU - Ren, Jiahuan AU - Long, Teng AU - Gu, Chunling AU - An, Cunbin AU - Fu, Hongbing AU - Schumacher, Stefan AU - Liao, Qing ID - 47533 T2 - arXiv:2309.07652 TI - Photochemical reaction enabling the engineering of photonic spin-orbit coupling in organic-crystal optical microcavities ER - TY - GEN AB - 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. AU - Schneider, Tobias AU - Gao, Wenlong AU - Zentgraf, Thomas AU - Schumacher, Stefan AU - Ma, Xuekai ID - 47531 T2 - arXiv:2303.12593 TI - Topological edge and corner states in coupled wave lattices in nonlinear polariton condensates ER - TY - GEN AB - 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. AU - Wingenbach, Jan AU - Schumacher, Stefan AU - Ma, Xuekai ID - 47529 T2 - arXiv:2305.04855 TI - Tweaking Spectral Topology and Exceptional Points by Nonlinearity in Non-Hermitian Polariton Systems ER - TY - CHAP AU - Zentgraf, Thomas ED - Panoiu, Nicoae C. ID - 47543 SN - 978-0-323-90614-2 T2 - Fundamentals and Applications of Nonlinear Nanophotonics TI - Symmetry governed nonlinear selection rules in nanophotonics ER - TY - JOUR AU - Tenberge, Claudia ID - 47868 JF - Grundschule Sachunterricht TI - Ungeliebte Tiere in der Stadt VL - 98 ER - TY - BOOK ED - ija Grigorjevaite, Kadri Mettis, Katarina Stekic, Kristof Van de Keere, Marjana Brkic, Michael Lenke, Mikko-Jussi Laakso, Paulius Lukas Tamošiūnas, Sofia Karlsson, Sven Hüsing, Jurga Turčinavičienė, Violeta Šlekienė, Mart Laanpere, and Vidita Urboniene ID - 47885 TI - A PRACTICAL HANDBOOK ON EFFECTIVE DEVELOPMENT AND IMPLEMENTATION OF STEAM TEACHING AT SCHOOL ER - TY - CHAP AU - Schröer, Franz AU - Tenberge, Claudia ED - Wooff, D. , McLain, M. ID - 47886 T2 - Bloomsbury Handbook of Technology Education. TI - Inclusion and the Development of Technology Education - Thinking towards an inclusive curriculum for technology education in German primary schools ER - TY - CONF AU - Jordans, Melanie AU - Riese, Josef ED - van Vorst, Helena ID - 48633 T2 - Lernen, Lehren und Forschen in einer digital geprägten Welt. Gesellschaft für Didaktik der Chemie und Physik. Jahrestagung in Aachen 2022 TI - Unterrichtsplanung mit sinnvoller Einbettung digitaler Medien im PU ER - TY - JOUR AB - An ultra-fast change of the absorption onset for zincblende gallium-nitride (zb-GaN) (fundamental bandgap: 3.23 eV) is observed by investigating the imaginary part of the dielectric function using time-dependent femtosecond pump–probe spectroscopic ellipsometry between 2.9 and 3.7 eV. The 266 nm (4.66 eV) pump pulses induce a large electron–hole pair concentration up to 4×1020cm−3, which shift the transition energy between conduction and valence bands due to many-body effects up to ≈500 meV. Here, the absorption onset increases due to band filling while the bandgap renormalization at the same time decreases the bandgap. Additionally, the absorption of the pump-beam creates a free-carrier profile within the 605 nm zb-GaN layer with high free-carrier concentrations at the surface, and low concentrations at the interface to the substrate. This leads to varying optical properties from the sample surface (high transition energy) to substrate (low transition energy), which are taken into account by grading analysis for an accurate description of the experimental data. For this, a model describing the time- and position-dependent free-carrier concentration is formulated by considering the relaxation, recombination, and diffusion of those carriers. We provide a quantitative analysis of optical experimental data (ellipsometric angles Ψ and Δ) as well as a plot for the time-dependent change of the imaginary part of the dielectric function. AU - Baron, Elias AU - Goldhahn, Rüdiger AU - Espinoza, Shirly AU - Zahradník, Martin AU - Rebarz, Mateusz AU - Andreasson, Jakob AU - Deppe, Michael AU - As, Donat Josef AU - Feneberg, Martin ID - 46573 IS - 7 JF - Journal of Applied Physics KW - General Physics and Astronomy SN - 0021-8979 TI - Time-resolved pump–probe spectroscopic ellipsometry of cubic GaN. I. Determination of the dielectric function VL - 134 ER - TY - JOUR AB - The crystal family of potassium titanyl phosphate (KTiOPO4) is a promising material group for applications in quantum and nonlinear optics. The fabrication of low-loss optical waveguides, as well as high-grade periodically poled ferroelectric domain structures, requires a profound understanding of the material properties and crystal structure. In this regard, Raman spectroscopy offers the possibility to study and visualize domain structures, strain, defects, and the local stoichiometry, which are all factors impacting device performance. However, the accurate interpretation of Raman spectra and their changes with respect to extrinsic and intrinsic defects requires a thorough assignment of the Raman modes to their respective crystal features, which to date is only partly conducted based on phenomenological modelling. To address this issue, we calculated the phonon spectra of potassium titanyl phosphate and the related compounds rubidium titanyl phosphate (RbTiOPO4) and potassium titanyl arsenate (KTiOAsO4) based on density functional theory and compared them with experimental data. Overall, this allows us to assign various spectral features to eigenmodes of lattice substructures with improved detail compared to previous assignments. Nevertheless, the analysis also shows that not all features of the spectra can unambigiously be explained yet. A possible explanation might be that defects or long range fields not included in the modeling play a crucial rule for the resulting Raman spectrum. In conclusion, this work provides an improved foundation into the vibrational properties in the KTiOPO4 material family. AU - Neufeld, Sergej AU - Gerstmann, Uwe AU - Padberg, Laura AU - Eigner, Christof AU - Berth, Gerhard AU - Silberhorn, Christine AU - Eng, Lukas M. AU - Schmidt, Wolf Gero AU - Rüsing, Michael ID - 47997 IS - 10 JF - Crystals KW - Inorganic Chemistry KW - Condensed Matter Physics KW - General Materials Science KW - General Chemical Engineering SN - 2073-4352 TI - Vibrational Properties of the Potassium Titanyl Phosphate Crystal Family VL - 13 ER - TY - JOUR AB - We report a titanium indiffused waveguide resonator featuring an integrated electro-optic modulator for cavity length stabilisation that produces close to 5 dB of squeezed light at 1550 nm (2.4 dB directly measured). The resonator is locked on resonance for tens of minutes with 70 mW of SH light incident on the cavity, demonstrating that photorefraction can be mitigated. Squeezed light production concurrent with cavity length stabilisation utilising the integrated EOM is demonstrated. The device demonstrates the suitability of this platform for squeezed light generation in network applications, where stabilisation to the reference field is typically necessary. AU - Stefszky, M. AU - vom Bruch, F. AU - Santandrea, M. AU - Ricken, R. AU - Quiring, V. AU - Eigner, C. AU - Herrmann, H AU - Silberhorn, C ID - 48349 IS - 21 JF - Optics Express KW - Atomic and Molecular Physics KW - and Optics SN - 1094-4087 TI - Lithium niobate waveguide squeezer with integrated cavity length stabilisation for network applications VL - 31 ER - TY - JOUR AU - Gao, Ying AU - Ma, Xuekai AU - Zhai, Xiaokun AU - Xing, Chunzi AU - Gao, Meini AU - Dai, Haitao AU - Wu, Hao AU - Liu, Tong AU - Ren, Yuan AU - Wang, Xiao AU - Pan, Anlian AU - Hu, Wei AU - Schumacher, Stefan AU - Gao, Tingge ID - 48774 IS - 20 JF - Physical Review B SN - 2469-9950 TI - Single-shot spatial instability and electric control of polariton condensates at room temperature VL - 108 ER - TY - JOUR AU - Ali, Usman AU - Holthaus, Martin AU - Meier, Torsten ID - 49059 IS - 4 JF - Physical Review Research KW - General Physics and Astronomy SN - 2643-1564 TI - Chirped Bloch-harmonic oscillations in a parametrically forced optical lattice VL - 5 ER - TY - JOUR AU - Scharwald, D. AU - Meier, T. AU - Sharapova, P. R. ID - 49117 IS - 4 JF - Physical Review Research KW - General Physics and Astronomy SN - 2643-1564 TI - Phase sensitivity of spatially broadband high-gain SU(1,1) interferometers VL - 5 ER - TY - CHAP AU - Bürger, Julius AU - Lindner, Jörg K. N. ED - Bürger, Julius ID - 46980 SN - 978-3-8376-6377-8 T2 - Climate Protection, Resource Efficiency, and Sustainable Mobility - Transdisciplinary Approaches to Design and Manufacturing Technology TI - Transmission electron microscopy and transdisciplinary research ER - TY - CHAP AU - Bürger, Julius AU - Lindner, Jörg K. N. ID - 47133 SN - 978-3-8376-6377-8 T2 - Climate Protection, Resource Efficiency, and Sustainable Mobility - Transdisciplinary Approaches to Design and Manufacturing Technology TI - Transmission electron microscopy and transdisciplinary research ER - TY - CHAP AU - Bürger, Julius AU - Lindner, Jörg K. N. ID - 47123 SN - 978-3-8376-6377-8 T2 - Climate Protection, Resource Efficiency, and Sustainable Mobility - Transdisciplinary Approaches to Design and Manufacturing Technology TI - Transmission electron microscopy and transdisciplinary research ER - TY - GEN ED - Lindner, Jörg ED - Brassat, Katharina ID - 49367 SN - ISSN 2073-4360 T2 - Polymers TI - Self-Assembled Block Copolymer Thin Films and Their Applications ER - TY - JOUR AB - In this work, we utilize thin dielectric meta-atoms placed on a silver substrate to efficiently enhance and manipulate the third-harmonic generation. We theoretically and experimentally reveal that when the structural symmetry of the meta-atom is incompatible with the lattice symmetry of an array, some generalized nonlinear geometric phases appear, which offers new possibilities for harmonic generation control beyond the accessible symmetries governed by the selection rule. The underlying mechanism is attributed to the modified rotation of the effective principal axis of a dense meta-atom array, where the strong coupling among the units gives rise to a generalized linear geometric phase modulation of the pump light. Therefore, nonlinear geometric phases carried by third-harmonic emissions are the natural result of the wave-mixing process among the modes excited at the fundamental frequency. This mechanism further points out a new strategy to predict the nonlinear geometric phases delivered by the nanostructures according to their linear responses. Our design is simple and efficient and offers alternatives for the nonlinear meta-devices that are capable of flexible photon generation and manipulation. AU - Liu, Bingyi AU - Geromel, René AU - Su, Zhaoxian AU - Guo, Kai AU - Wang, Yongtian AU - Guo, Zhongyi AU - Huang, Lingling AU - Zentgraf, Thomas ID - 49607 JF - ACS Photonics KW - Electrical and Electronic Engineering KW - Atomic and Molecular Physics KW - and Optics KW - Biotechnology KW - Electronic KW - Optical and Magnetic Materials SN - 2330-4022 TI - Nonlinear Dielectric Geometric-Phase Metasurface with Simultaneous Structure and Lattice Symmetry Design ER - TY - JOUR AU - Ruiz Alvarado, Isaac Azahel AU - Zare Pour, Mohammad Amin AU - Hannappel, Thomas AU - Schmidt, Wolf Gero ID - 49634 IS - 4 JF - Physical Review B SN - 2469-9950 TI - Structural fingerprints in the reflectance anisotropy of AlInP(001) VL - 108 ER - TY - GEN AB - 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 we focus on the generation of pairs of photons with high degrees of polarization entanglement and simultaneously high indistinguishibility. We achieve this goal by selectively reducing the biexciton lifetime with an optical resonator. We demonstrate 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 two-fold degenerate optical modes. Our 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. We report non-trivial dependencies on system parameters and use the predictive power of our combined theoretical approach to determine the optimal range of Purcell enhancement that maximizes indistinguishability and entanglement to near unity values in the telecom C-band at $1550\,\mathrm{nm}$. AU - Bauch, David AU - Siebert, Dustin AU - Jöns, Klaus AU - Förstner, Jens AU - Schumacher, Stefan ID - 43246 KW - tet_topic_phc KW - tet_topic_qd TI - On-demand indistinguishable and entangled photons at telecom frequencies using tailored cavity designs ER - TY - JOUR AU - Ali, Usman AU - Holthaus, Martin AU - Meier, Torsten ID - 52122 IS - 4 JF - Physical Review Research KW - General Physics and Astronomy SN - 2643-1564 TI - Chirped Bloch-harmonic oscillations in a parametrically forced optical lattice VL - 5 ER - TY - DATA AU - Meier, Torsten ID - 52124 TI - Chirped Bloch-harmonic oscillations in a parametrically forced optical lattice ER - TY - JOUR AU - Diederich, Malte AU - Spatz, Verena AU - Bauer, Anna Brigitte ID - 52358 JF - Phydid B, Didaktik der Physik, Beiträge zur DPG-Frühjahrstagung (2022) TI - Auswirkungen einer Online-Intervention (Mindset, Lerntechniken) auf den Studieneinstieg ER - TY - JOUR AU - Widhalm, Alex AU - Golla, Christian AU - Weber, Nils AU - Mackwitz, Peter AU - Zrenner, Artur AU - Meier, Cedrik ID - 29716 IS - 4 JF - Optics Express KW - Atomic and Molecular Physics KW - and Optics SN - 1094-4087 TI - Electric-field-induced second harmonic generation in silicon dioxide VL - 30 ER -