@article{13429, author = {{Bocchini, Adriana and Neufeld, Sergej and Gerstmann, Uwe and Schmidt, Wolf Gero}}, issn = {{0953-8984}}, journal = {{Journal of Physics: Condensed Matter}}, pages = {{385401}}, title = {{{Oxygen and potassium vacancies in KTP calculated from first principles}}}, doi = {{10.1088/1361-648x/ab295c}}, volume = {{31}}, year = {{2019}}, } @article{20578, author = {{Driben, R and Ma, Xuekai and Schumacher, Stefan and Meier, Torsten}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{6}}, pages = {{1327--1330}}, title = {{{Bloch oscillations of multidimensional dark soliton wave packets and light bullets}}}, doi = {{10.1364/ol.44.001327}}, volume = {{44}}, year = {{2019}}, } @article{15851, author = {{Ma, Xuekai and Kartashov, Yaroslav Y and Gao, Tingge and Schumacher, Stefan}}, issn = {{1367-2630}}, journal = {{New Journal of Physics}}, title = {{{Controllable high-speed polariton waves in a PT-symmetric lattice}}}, doi = {{10.1088/1367-2630/ab5a9b}}, volume = {{21}}, year = {{2019}}, } @unpublished{13340, abstract = {{Spontaneous formation of transverse patterns is ubiquitous in nonlinear dynamical systems of all kinds. An aspect of particular interest is the active control of such patterns. In nonlinear optical systems this can be used for all-optical switching with transistor-like performance, for example realized with polaritons in a planar quantum-well semiconductor microcavity. Here we focus on a specific configuration which takes advantage of the intricate polarization dependencies in the interacting optically driven polariton system. Besides detailed numerical simulations of the coupled light-field exciton dynamics, in the present paper we focus on the derivation of a simplified population competition model giving detailed insight into the underlying mechanisms from a nonlinear dynamical systems perspective. We show that such a model takes the form of a generalized Lotka-Volterra system for two competing populations explicitly including a source term that enables external control. We present a comprehensive analysis both of the existence and stability of stationary states in the parameter space spanned by spatial anisotropy and external control strength. We also construct phase boundaries in non-trivial regions and characterize emerging bifurcations. The population competition model reproduces all key features of the switching observed in full numerical simulations of the rather complex semiconductor system and at the same time is simple enough for a fully analytical understanding of the system dynamics.}}, author = {{Pukrop, Matthias and Schumacher, Stefan}}, booktitle = {{arXiv:1903.12534}}, title = {{{Externally Controlled Lotka-Volterra Dynamics in a Linearly Polarized Polariton Fluid}}}, year = {{2019}}, } @unpublished{13347, abstract = {{<div> <div> <div> <p>Molecular doping in conjugated polymers is a crucial process for their application in organic photovoltaics and optoelectronics. In the present work we theoretically investigate p-type molecu- lar doping in a series of (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b”]dithiophene)-alt- 4,7-(2,1,3-benzothiadiazole)] (PCPDT-BT) conjugated oligomers with different lengths and three widely-used dopants with different electron affinities, namely F4TCNQ, F6TCNNQ, and CN6-CP. We study in detail the molecular geometry of possible oligomer-dopant complexes and its influence on the doping mechanisms and electronic system properties. We find that the mechanisms of dop- ing and charge transfer observed sensitively depend on the specific geometry of the oligomer-dopant complexes. For a given complex different geometries may exist, some of which show transfer of an entire electron from the oligomer chain onto the dopant molecule resulting in an integer-charge transfer complex, leaving the system in a ground state with broken spin symmetry. In other ge- ometries merely hybridization of oligomer and dopant frontier orbitals occurs with partial charge transfer but spin-symmetric ground state. Considering the resulting electronic density of states both cases may well contribute to an increased electrical conductivity of corresponding film samples while the underlying physical mechanisms are entirely different. </p> </div> </div> </div>}}, author = {{Dong, Chuan-Ding and Schumacher, Stefan}}, title = {{{Molecular Doping of PCPDT-BT Copolymers: Comparison of Molecular Complexes with and Without Integer Charge Transfer}}}, year = {{2019}}, } @article{13343, author = {{Vollbrecht, Joachim and Wiebeler, Christian and Bock, Harald and Schumacher, Stefan and Kitzerow, Heinz-Siegfried}}, issn = {{1932-7447}}, journal = {{The Journal of Physical Chemistry C}}, number = {{7}}, pages = {{4483--4492}}, title = {{{Curved Polar Dibenzocoronene Esters and Imides versus Their Planar Centrosymmetric Homologs: Photophysical and Optoelectronic Analysis}}}, doi = {{10.1021/acs.jpcc.8b10730}}, volume = {{123}}, year = {{2019}}, } @article{40384, author = {{Ferreri, Alessandro and Ansari, V. and Silberhorn, Christine and Sharapova, Polina R.}}, issn = {{2469-9926}}, journal = {{Physical Review A}}, number = {{5}}, publisher = {{American Physical Society (APS)}}, title = {{{Temporally multimode four-photon Hong-Ou-Mandel interference}}}, doi = {{10.1103/physreva.100.053829}}, volume = {{100}}, year = {{2019}}, } @article{26305, author = {{Bohmann, M. and Tiedau, J. and Bartley, Tim and Sperling, Jan and Silberhorn, Christine and Vogel, W.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, title = {{{Incomplete Detection of Nonclassical Phase-Space Distributions}}}, doi = {{10.1103/physrevlett.120.063607}}, year = {{2018}}, } @inproceedings{40388, author = {{Luo, Kai Hong and Brauner, Sebastian and Eigner, Christof and Sharapova, Polina and Ricken, Raimund and Meier, Torsten and Herrmann, Harald and Silberhorn, Christine}}, booktitle = {{Conference on Lasers and Electro-Optics}}, isbn = {{978-1-943580-42-2}}, location = {{San Jose, California United States}}, publisher = {{OSA}}, title = {{{Monolithically Integrated Hong-Ou-Mandel Experiment in LiNbO3}}}, doi = {{10.1364/cleo_qels.2018.fm1g.3}}, year = {{2018}}, } @inbook{43193, abstract = {{Short laser pulses are able to generate material excitations with a well-defined phase which is imposed by the optical excitation source. The generated coherent superposition state be described as an optical polarization which exists only in non-equilibrium situations. The coherence, i.e., the phase relations between the optical transitions that originate from the excitation, leads to several interesting effects in time-resolved linear and nonlinear optical spectroscopy. In this article, the basic principles that underlie these coherent transients are introduced and several examples are presented.}}, author = {{Meier, Torsten and Koch, S.W.}}, booktitle = {{Encyclopedia of Modern Optics (Second Edition)}}, editor = {{Guenther, Bob and Steel, Duncan}}, pages = {{264--277}}, publisher = {{Elsevier}}, title = {{{Foundations of Coherent Transients in Semiconductors}}}, doi = {{10.1016/B978-0-12-803581-8.09564-3}}, volume = {{4}}, year = {{2018}}, } @article{4370, author = {{Schmidt, C. and Bühler, J. and Heinrich, A.-C. and Allerbeck, J. and Podzimski, R. and Berghoff, D. and Meier, Torsten and Schmidt, Wolf Gero and Reichl, C. and Wegscheider, W. and Brida, D. and Leitenstorfer, A.}}, issn = {{2041-1723}}, journal = {{Nature Communications}}, number = {{1}}, publisher = {{Springer Nature}}, title = {{{Signatures of transient Wannier-Stark localization in bulk gallium arsenide}}}, doi = {{10.1038/s41467-018-05229-x}}, volume = {{9}}, year = {{2018}}, } @article{10018, author = {{Schmidt, Claudia and Bühler, J. and Heinrich, A.-C. and Allerbeck, J. and Podzimski, R. and Berghoff, Daniel and Meier, Torsten and Schmidt, Wolf Gero and Reichl, C. and Wegscheider, W. and Brida, D. and Leitenstorfer, A.}}, issn = {{2041-1723}}, journal = {{Nature Communications}}, title = {{{Signatures of transient Wannier-Stark localization in bulk gallium arsenide}}}, doi = {{10.1038/s41467-018-05229-x}}, volume = {{9}}, year = {{2018}}, } @article{4369, author = {{Geiger, Zachary A. and Fujiwara, Kurt M. and Singh, Kevin and Senaratne, Ruwan and Rajagopal, Shankari V. and Lipatov, Mikhail and Shimasaki, Toshihiko and Driben, Rodislav and Konotop, Vladimir V. and Meier, Torsten and Weld, David M.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, number = {{21}}, publisher = {{American Physical Society (APS)}}, title = {{{Observation and Uses of Position-Space Bloch Oscillations in an Ultracold Gas}}}, doi = {{10.1103/physrevlett.120.213201}}, volume = {{120}}, year = {{2018}}, } @article{13286, author = {{Geiger, Zachary A. and Fujiwara, Kurt M. and Singh, Kevin and Senaratne, Ruwan and Rajagopal, Shankari V. and Lipatov, Mikhail and Shimasaki, Toshihiko and Driben, Rodislav and Konotop, Vladimir V. and Meier, Torsten and Weld, David M.}}, issn = {{0031-9007}}, journal = {{Physical Review Letters}}, number = {{21}}, title = {{{Observation and Uses of Position-Space Bloch Oscillations in an Ultracold Gas}}}, doi = {{10.1103/physrevlett.120.213201}}, volume = {{120}}, year = {{2018}}, } @article{13287, author = {{Driben, R. and Konotop, V. V. and Malomed, B. A. and Meier, Torsten and Yulin, A. V.}}, issn = {{2470-0045}}, journal = {{Physical Review E}}, number = {{6}}, title = {{{Nonlinearity-induced localization in a periodically driven semidiscrete system}}}, doi = {{10.1103/physreve.97.062210}}, volume = {{97}}, year = {{2018}}, } @inproceedings{43859, abstract = {{Sub-cycle transmission measurements of bulk gallium arsenide biased by intense mid-infrared transients reveal a strong blue-shift of the optical absorption when the peak electric field reaches 10 MV/cm, indicating 2D-localization of electronic wave functions.}}, author = {{Meier, Torsten and Bühler, Johannes and Schmidt, Christian and Heinrich, A-C. and Allerbeck, Jonas and Podzimski, Reinold and Berghoff, Daniel and Schmidt, Wolf Gero and Reichl, Christian and Wegscheider, Werner and Brida, Daniele and Leitenstorfer, Alfred}}, booktitle = {{CLEO: QELS_Fundamental Science}}, isbn = {{978-1-943580-42-2}}, location = {{San Jose, California United States}}, pages = {{FF3P.7}}, publisher = {{Optical Society of America}}, title = {{{Wannier-Stark Localization in Bulk Gallium Arsenide Induced by Extreme Mid-Infrared Fields}}}, doi = {{10.1364/CLEO_QELS.2018.FF3P.7}}, year = {{2018}}, } @inproceedings{13901, author = {{Akimov, Ilya and Poltavtsev, Sergey V. and Salewski, Matthias and Yugova, Irina A. and Karczewski, Grzegorz and Wojtowicz, Tomasz and Maciej, Wiater and Reichelt, Matthias and Meier, Torsten and Yakovlev, Dmitri and Bayer, Manfred}}, booktitle = {{Ultrafast Phenomena and Nanophotonics XXII}}, editor = {{Betz, Markus and Elezzabi, Abdulhakem Y.}}, isbn = {{9781510615458}}, publisher = {{SPIE}}, title = {{{Coherent optical spectroscopy of charged exciton complexes in semiconductor nanostructures}}}, doi = {{10.1117/12.2288788}}, volume = {{10530}}, year = {{2018}}, } @inproceedings{4366, author = {{Akimov, Ilya and Poltavtsev, Sergey V. and Salewski, Matthias and Yugova, Irina A. and Karczewski, Grzegorz and Wojtowicz, Tomasz and Maciej , Wiater and Reichelt, Matthias and Meier, Torsten and Yakovlev, Dmitri and Bayer, Manfred}}, booktitle = {{Ultrafast Phenomena and Nanophotonics XXII}}, editor = {{Betz, Markus and Elezzabi, Abdulhakem Y.}}, isbn = {{9781510615458}}, publisher = {{SPIE}}, title = {{{Coherent optical spectroscopy of charged exciton complexes in semiconductor nanostructures}}}, doi = {{10.1117/12.2288788}}, volume = {{10530}}, year = {{2018}}, } @article{13405, author = {{Müller, Patrick and Karhan, Kristof and Krack, Matthias and Gerstmann, Uwe and Schmidt, Wolf Gero and Bauer, Matthias and Kühne, Thomas D.}}, issn = {{0192-8651}}, journal = {{Journal of Computational Chemistry}}, pages = {{712--716}}, title = {{{Impact of finite-temperature and condensed-phase effects on theoretical X-ray absorption spectra of transition metal complexes}}}, doi = {{10.1002/jcc.25641}}, year = {{2018}}, } @article{13406, author = {{Mamiyev, Z. and Lichtenstein, T. and Tegenkamp, C. and Braun, Christian and Schmidt, Wolf Gero and Sanna, S. and Pfnür, H.}}, issn = {{2475-9953}}, journal = {{Physical Review Materials}}, number = {{6}}, title = {{{Plasmon spectroscopy: Robust metallicity of Au wires on Si(557) upon oxidation}}}, doi = {{10.1103/physrevmaterials.2.066002}}, volume = {{2}}, year = {{2018}}, }