@article{4244, abstract = {{In this work we study the resonant and coherent properties of single InP-based InAs quantum dots, which show an optical emission in the telecom C-band and L-band. High-resolution resonant photocurrent spectroscopy on p–i–n devices reveals narrow linewidths and fully resolved fine structure splittings. We observe Lorentzian line shapes, which allow for the extraction of dephasing times as a function of the applied bias voltage. Coherent ps laser excitation results in pronounced Rabi rotations with increasing pulse area. For π-pulse excitation, we obtain more than 93 % of the theoretically expected photocurrent amplitude. Our results also demonstrate that such state-of-the-art InP-based quantum dots for the telecom band exhibit promising key parameters comparable to well-established InAs/GaAs counterparts.}}, author = {{Gordon, S. and Yacob, M. and Reithmaier, J. P. and Benyoucef, M. and Zrenner, Artur}}, issn = {{0946-2171}}, journal = {{Applied Physics B}}, keywords = {{Bias Voltage, Optical Parametric Oscillator, Molecular Beam Epitaxy Growth, Internal Electric Field, Dephasing Time}}, number = {{2}}, publisher = {{Springer Nature}}, title = {{{Coherent photocurrent spectroscopy of single InP-based quantum dots in the telecom band at 1.5 µm}}}, doi = {{10.1007/s00340-015-6279-6}}, volume = {{122}}, year = {{2016}}, } @article{1460, author = {{Xiao, Shiyi and Mühlenbernd, Holger and Li, Guixin and Kenney, Mitchell and Liu, Fu and Zentgraf, Thomas and Zhang, Shuang and Li, Jensen}}, issn = {{2195-1071}}, journal = {{Advanced Optical Materials}}, number = {{5}}, pages = {{654--658}}, publisher = {{Wiley-Blackwell}}, title = {{{Helicity-Preserving Omnidirectional Plasmonic Mirror}}}, doi = {{10.1002/adom.201500705}}, volume = {{4}}, year = {{2016}}, } @article{16323, author = {{Vollmers, Nora Jenny and Müller, Patrick and Hoffmann, Alexander and Herres-Pawlis, Sonja and Rohrmüller, Martin and Schmidt, Wolf Gero and Gerstmann, Uwe and Bauer, Matthias}}, issn = {{0020-1669}}, journal = {{Inorganic Chemistry}}, pages = {{11694--11706}}, title = {{{Experimental and Theoretical High-Energy-Resolution X-ray Absorption Spectroscopy: Implications for the Investigation of the Entatic State}}}, doi = {{10.1021/acs.inorgchem.6b01704}}, year = {{2016}}, } @article{1455, author = {{Zentgraf, Thomas}}, issn = {{0031-9252}}, journal = {{Physik in unserer Zeit}}, number = {{4}}, pages = {{163--164}}, publisher = {{Wiley-Blackwell}}, title = {{{Doppler-Effekt für rotierende Objekte}}}, doi = {{10.1002/piuz.201690063}}, volume = {{47}}, year = {{2016}}, } @inbook{29478, author = {{Sacher, Marc and Probst, Heike M. and Reinhold, Peter and Schaper, Niclas}}, booktitle = {{Leitkonzepte der Hochschuldidaktik}}, editor = {{Hartz, Stefanie and Marx, Sabine}}, isbn = {{9783763956135}}, pages = {{128--136}}, title = {{{Entwicklung eines kompetenzorientierten physikalischen Laborpraktikums}}}, doi = {{10.3278/6004485w}}, volume = {{128}}, year = {{2016}}, } @techreport{36303, author = {{Vogelsang, Christoph and Borowski, Andreas and Fischer, Hans and Kulgemeyer, Christoph and Reinhold, Peter and Riese, Josef and Schecker, Horst}}, publisher = {{Humboldt University & Johannes Gutenberg University}}, title = {{{ProfiLe-P+ – Professional Competence in Academic Physics Teacher Education}}}, volume = {{10}}, year = {{2016}}, } @article{4239, abstract = {{Confocal Raman spectroscopy is applied to identify ferroelectric domain structure sensitive phonon modes in potassium titanyl phosphate. Therefore, polarization-dependent measurements in various scattering configurations have been performed to characterize the fundamental Raman spectra of the material. The obtained spectra are discussed qualitatively based on an internal mode assignment. In the main part of this work, we have characterized z-cut periodically poled potassium titanyl phosphate in terms of polarity- and structure-sensitive phonon modes. Here, we find vibrations whose intensities are linked to the ferroelectric domain walls. We interpret this in terms of changes in the polarizability originating from strain induced by domain boundaries and the inner field distribution. Hence, a direct and 3D visualization of ferroelectric domain structures becomes possible in potassium titanyl phosphate.}}, author = {{Rüsing, Michael and Eigner, Christof and Mackwitz, P. and Berth, Gerhard and Silberhorn, Christine and Zrenner, Artur}}, issn = {{0021-8979}}, journal = {{Journal of Applied Physics}}, number = {{4}}, publisher = {{AIP Publishing}}, title = {{{Identification of ferroelectric domain structure sensitive phonon modes in potassium titanyl phosphate: A fundamental study}}}, doi = {{10.1063/1.4940964}}, volume = {{119}}, year = {{2016}}, } @article{3888, abstract = {{We successfully developed a process to fabricate freestanding cubic aluminium nitride (c-AlN) membranes containing cubic gallium nitride (c-GaN) quantum dots (QDs). The samples were grown by plasma assisted molecular beam epitaxy (MBE). To realize the photonic crystal (PhC) membrane we have chosen a triangular array of holes. The array was fabricated by electron beam lithography and several steps of reactive ion etching (RIE) with the help of a hard mask and an undercut of the active layer. The r/a- ratio of 0.35 was deter- mined by numerical simulations to obtain a preferably wide photonic band gap. Micro-photoluminescence (μ-PL) measurements of the photonic crystals, in particular of a H1 and a L3 cavity, and the emission of the QD ensemble were performed to characterize the samples. The PhCs show high quality factors of 4400 for the H1 cavity and about 5000/3000 for two different modes of the L3 cavity, respectively. The energy of the fundamental modes is in good agreement to the numerical simulations. }}, author = {{Blumenthal, Sarah and Bürger, Matthias and Hildebrandt, Andre and Förstner, Jens and Weber, Nils and Meier, Cedrik and Reuter, Dirk and As, Donat J.}}, issn = {{1862-6351}}, journal = {{physica status solidi (c)}}, keywords = {{tet_topic_phc, tet_topic_qd}}, number = {{5-6}}, pages = {{292--296}}, publisher = {{Wiley}}, title = {{{Fabrication and characterization of two-dimensional cubic AlN photonic crystal membranes containing zincblende GaN quantum dots}}}, doi = {{10.1002/pssc.201600010}}, volume = {{13}}, year = {{2016}}, } @article{4237, abstract = {{We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO2 layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the þz side.}}, author = {{Mackwitz, P. and Rüsing, Michael and Berth, Gerhard and Widhalm, A. and Müller, K. and Zrenner, Artur}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{15}}, publisher = {{AIP Publishing}}, title = {{{Periodic domain inversion in x-cut single-crystal lithium niobate thin film}}}, doi = {{10.1063/1.4946010}}, volume = {{108}}, year = {{2016}}, } @article{4240, abstract = {{Cubic gallium nitride (GaN) films are analyzed with highresolution X-ray diffraction (HRXRD) and Raman spectroscopy. Several cubic GaN layers were grown on 3C-SiC (001) substrate by radio-frequency plasma-assisted molecular beam epitaxy. The layer thickness of the cubic GaN was varied between 75 and 505 nm. The HRXRD analysis reveals a reduction of the full-width at half-maximum (FWHM) of omega scans for growing layer thicknesses, which is caused by a partial compensation of defects. The Raman characterization confirms well-formed c-GaN layers. A more detailed examination of the longitudinal optical mode hints at a correlation of the FWHM of the Raman mode with the dislocation density, which shows the possibility to determine dislocation densities by Ramanspectroscopy on a micrometer scale, which is not possible by HRXRD. Furthermore, this Raman analysis shows that normalized Raman spectra present an alternative way to determine layer thicknesses of thin GaN films.}}, author = {{Rüsing, Michael and Wecker, T. and Berth, Gerhard and As, Donat Josef and Zrenner, Artur}}, issn = {{0370-1972}}, journal = {{physica status solidi (b)}}, keywords = {{cubic gallium nitride, dislocation density, HRXRD, Raman spectroscopy}}, number = {{4}}, pages = {{778--782}}, publisher = {{Wiley}}, title = {{{Joint Raman spectroscopy and HRXRD investigation of cubic gallium nitride layers grown on 3C-SiC}}}, doi = {{10.1002/pssb.201552592}}, volume = {{253}}, year = {{2016}}, } @article{10026, abstract = {{Congruent lithium niobate and lithium tantalate mixed crystals have been grown over the complete compositional range with the Czochralski method. The structural and vibrational properties of the mixed crystals are studied extensively by x-ray diffraction measurements, Raman spectroscopy, and density functional theory. The measured lattice parameters and vibrational frequencies are in good agreement with our theoretical predictions. The observed dependence of the Raman frequencies on the crystal composition is discussed on the basis of the calculated phonon displacement patterns. The phononic contribution to the static dielectric tensor is calculated by means of the generalized Lyddane-Sachs-Teller relation. Due to the pronounced dependence of the optical response on the Ta concentration, lithium niobate tantalate mixed crystals represent a perfect model system to study the properties of uniaxial mixed ferroelectric materials for application in integrated optics.}}, author = {{Rüsing, Michael and Sanna, Simone and Neufeld, Sergej and Berth, Gerhard and Schmidt, Wolf Gero and Zrenner, Artur and Yu, H. and Wang, Y. and Zhang, H.}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, title = {{{Vibrational properties of LiNb1−xTaxO3 mixed crystals}}}, doi = {{10.1103/physrevb.93.184305}}, year = {{2016}}, } @article{9268, author = {{Harder, Georg and Bartley, Tim and Lita, Adriana E. and Nam, Sae Woo and Gerrits, Thomas and Silberhorn, Christine}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, title = {{{Single-Mode Parametric-Down-Conversion States with 50 Photons as a Source for Mesoscopic Quantum Optics}}}, doi = {{10.1103/physrevlett.116.143601}}, year = {{2016}}, } @inproceedings{37803, author = {{Blumberg, Eva and Fromme, Theresa and Hellmich, Frank}}, publisher = {{Freie Universität Berlin}}, title = {{{Förderung inklusiven Lernens im naturwissenschaftlich-technischen Sachunterricht der Grundschule. Vortrag auf der 4. Jahrestagung der Gesellschaft für Empirische Bildungsforschung (GEBF)}}}, year = {{2016}}, } @article{38061, author = {{Schleich, Wolfgang P. and Ranade, Kedar S. and Anton, Christian and Arndt, Markus and Aspelmeyer, Markus and Bayer, Manfred and Berg, Gunnar and Calarco, Tommaso and Fuchs, Harald and Giacobino, Elisabeth and Grassl, Markus and Hänggi, Peter and Heckl, Wolfgang M. and Hertel, Ingolf-Volker and Huelga, Susana and Jelezko, Fedor and Keimer, Bernhard and Kotthaus, Jörg P. and Leuchs, Gerd and Lütkenhaus, Norbert and Maurer, Ueli and Pfau, Tilman and Plenio, Martin B. and Rasel, Ernst Maria and Renn, Ortwin and Silberhorn, Christine and Schiedmayer, Jörg and Schmitt-Landsiedel, Doris and Schönhammer, Kurt and Ustinov, Alexey and Walther, Philip and Weinfurter, Harald and Welzl, Emo and Wiesendanger, Roland and Wolf, Stefan and Zeilinger, Anton and Zoller, Peter}}, issn = {{0946-2171}}, journal = {{Applied Physics B}}, keywords = {{General Physics and Astronomy, Physics and Astronomy (miscellaneous), General Engineering}}, number = {{5}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Quantum technology: from research to application}}}, doi = {{10.1007/s00340-016-6353-8}}, volume = {{122}}, year = {{2016}}, } @article{38068, author = {{Szemendera, L. and Darré, P. and Baudoin, R. and Grossard, L. and Delage, L. and Herrmann, Harald and Silberhorn, Christine and Reynaud, F.}}, issn = {{0035-8711}}, journal = {{Monthly Notices of the Royal Astronomical Society}}, keywords = {{Space and Planetary Science, Astronomy and Astrophysics}}, number = {{3}}, pages = {{3115--3118}}, publisher = {{Oxford University Press (OUP)}}, title = {{{In-lab ALOHA mid-infrared up-conversion interferometer with high fringe contrast @λ = 3.39 μm}}}, doi = {{10.1093/mnras/stw196}}, volume = {{457}}, year = {{2016}}, } @article{38071, author = {{Harder, G. and Silberhorn, Christine and Rehacek, J. and Hradil, Z. and Motka, L. and Stoklasa, B. and Sánchez-Soto, L. L.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, keywords = {{General Physics and Astronomy}}, number = {{13}}, publisher = {{American Physical Society (APS)}}, title = {{{Local Sampling of the Wigner Function at Telecom Wavelength with Loss-Tolerant Detection of Photon Statistics}}}, doi = {{10.1103/physrevlett.116.133601}}, volume = {{116}}, year = {{2016}}, } @article{13917, abstract = {{We present the synthesis of indium oxide (In2O3) inverse opal films with photonic stop bands in the visible range by a structure replication method. Artificial opal films made of poly(methyl methacrylate) (PMMA) spheres are utilized as template. The opal films are deposited via sedimentation facilitated by ultrasonication, and then impregnated by indium nitrate solution, which is thermally converted to In2O3 after drying. The quality of the resulting inverse opal film depends on many parameters; in this study the water content of the indium nitrate/PMMA composite after drying is investigated. Comparison of the reflectance spectra recorded by vis-spectroscopy with simulated data shows a good agreement between the peak position and calculated stop band positions for the inverse opals. This synthesis is less complex and highly efficient compared to most other techniques and is suitable for use in many applications.}}, author = {{Amrehn, Sabrina and Berghoff, Daniel and Nikitin, Andreas and Reichelt, Matthias and Wu, Xia and Meier, Torsten and Wagner, Thorsten}}, issn = {{1569-4410}}, journal = {{Photonics and Nanostructures - Fundamentals and Applications}}, pages = {{55--63}}, title = {{{Indium oxide inverse opal films synthesized by structure replication method}}}, doi = {{10.1016/j.photonics.2016.02.005}}, volume = {{19}}, year = {{2016}}, } @article{13915, abstract = {{The dynamics of a pair of harmonic oscillators represented by three-dimensional fields coupled with a repulsive cubic nonlinearity is investigated through direct simulations of the respective field equations and with the help of the finite-mode Galerkin approximation (GA), which represents the two interacting fields by a superposition of 3+3 harmonic-oscillator p-wave eigenfunctions with orbital and magnetic quantum numbers l=1 and m=1, 0, −1. The system can be implemented in binary Bose-Einstein condensates, demonstrating the potential of the atomic condensates to emulate various complex modes predicted by classical field theories. First, the GA very accurately predicts a broadly degenerate set of the system's ground states in the p-wave manifold, in the form of complexes built of a dipole coaxial with another dipole or vortex, as well as complexes built of mutually orthogonal dipoles. Next, pairs of noncoaxial vortices and/or dipoles, including pairs of mutually perpendicular vortices, develop remarkably stable dynamical regimes, which feature periodic exchange of the angular momentum and periodic switching between dipoles and vortices. For a moderately strong nonlinearity, simulations of the coupled-field equations agree very well with results produced by the GA, demonstrating that the dynamics is accurately spanned by the set of six modes limited to l=1.}}, author = {{Driben, R. and Konotop, V. V. and Malomed, B. A. and Meier, Torsten}}, issn = {{2470-0045}}, journal = {{Physical Review E}}, number = {{1}}, title = {{{Dynamics of dipoles and vortices in nonlinearly coupled three-dimensional field oscillators}}}, doi = {{10.1103/physreve.94.012207}}, volume = {{94}}, year = {{2016}}, } @inproceedings{13918, author = {{Podzimski, Reinold and Duc, Huynh Thanh and Priyadarshi, Shekhar and Schmidt, Christian and Bieler, Mark and Meier, Torsten}}, booktitle = {{Ultrafast Phenomena and Nanophotonics XX}}, editor = {{Betz, Markus and Elezzabi, Abdulhakem Y.}}, publisher = {{SPIE}}, title = {{{Photocurrents in semiconductors and semiconductor quantum wells analyzed by k.p-based Bloch equations}}}, doi = {{10.1117/12.2208572}}, volume = {{9746}}, year = {{2016}}, } @article{22942, abstract = {{A microscopic approach that is based on the multisubband semiconductor Bloch equations formulated in the basis of a 14-band k⋅p model is employed to compute the temporal dynamics of photocurrents in GaAs quantum wells following excitation with femtosecond laser pulses. This approach provides a transparent description of the interband, intersubband, and intraband excitations, fully includes all resonant as well as off-resonant excitations, and treats the light-matter interaction nonperturbatively. For linearly polarized excitations, the photocurrents contain contributions from shift and rectification currents. We numerically compute and analyze these currents generated by excitation with femtosecond laser pulses for [110]- and [111]-oriented GaAs quantum wells. It is shown that the often employed perturbative χ(2) approach breaks down for peak fields larger than about 10 kV/cm, and that nonperturbative effects lead to a reduction of the peak values of the shift and rectification currents and to temporal oscillations that originate from Rabi flopping. In particular, we find a complex oscillatory photon energy dependence of the magnitudes of the shift and rectification currents. Our simulations demonstrate that this dependence is the result of mixing between the heavy- and light-hole valence bands. This is a surprising finding since the band mixing has an even larger influence on the strength of the photocurrents than the absorption coefficient. For [110]-oriented GaAs quantum wells, the calculated photon energy dependence is compared to experimental results, and good agreement is obtained. This validates our theoretical approach.}}, author = {{Duc, Huynh Thanh and Podzimski, Reinold and Priyadarshi, Shekhar and Bieler, Mark and Meier, Torsten}}, issn = {{2469-9950}}, journal = {{Physical Review B}}, number = {{8}}, publisher = {{American Physical Society}}, title = {{{Ultrafast shift and rectification photocurrents in GaAs quantum wells: Excitation intensity dependence and the importance of band mixing}}}, doi = {{10.1103/physrevb.94.085305}}, volume = {{94}}, year = {{2016}}, }