@article{13856, author = {{Schmidt, Wolf Gero and Wenzien, B. and Bechstedt, F.}}, issn = {{0163-1829}}, journal = {{Physical Review B}}, number = {{7}}, pages = {{4731--4744}}, title = {{{Chemisorption of antimony on GaAs(110)}}}, doi = {{10.1103/physrevb.49.4731}}, volume = {{49}}, year = {{1994}}, } @article{13855, author = {{Schmidt, Wolf Gero and Wenzien, Bernd and Bechstedt, Friedhelm}}, issn = {{0039-6028}}, journal = {{Surface Science}}, number = {{Part A}}, pages = {{235--240}}, title = {{{Coverage-dependent bonding of Sb on GaAs (110)}}}, doi = {{10.1016/0039-6028(94)90400-6}}, volume = {{307-309}}, year = {{1994}}, } @article{13853, author = {{Bechstedt, F and Schmidt, Wolf Gero and Wenzien, B}}, issn = {{0295-5075}}, journal = {{Europhysics Letters (EPL)}}, number = {{5}}, pages = {{357--362}}, title = {{{Energetics and Structure of Ordered Sb Overlayers and Sb Clusters on GaAs(110) Probed by Ab Initio Calculations}}}, doi = {{10.1209/0295-5075/25/5/008}}, volume = {{25}}, year = {{1994}}, } @article{13854, author = {{Schmidt, Wolf Gero and Srivastava, GP}}, issn = {{0038-1098}}, journal = {{Solid State Communications}}, number = {{4}}, pages = {{345--348}}, title = {{{First principles calculations of interface phonons of an Epitaxial Sb monolayer on GaAs(110) and InP(110)}}}, doi = {{10.1016/0038-1098(94)90597-5}}, volume = {{89}}, year = {{1994}}, } @article{35389, author = {{Schnepp, W. and Disch, S. and Schmidt, Claudia}}, issn = {{0267-8292}}, journal = {{Liquid Crystals}}, keywords = {{Condensed Matter Physics, General Materials Science, General Chemistry}}, number = {{3}}, pages = {{843--852}}, publisher = {{Informa UK Limited}}, title = {{{2H NMR study on the lyomesophases of the system hexaethylene glycol dodecyl methyl ether/water Temperature dependence of quadrupole splittings}}}, doi = {{10.1080/02678299308027761}}, volume = {{14}}, year = {{1993}}, } @article{35387, author = {{Rosen, M. E. and Rucker, S. P. and Schmidt, Claudia and Pines, A.}}, issn = {{0022-3654}}, journal = {{The Journal of Physical Chemistry}}, keywords = {{Physical and Theoretical Chemistry, General Engineering}}, number = {{15}}, pages = {{3858--3866}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Two-dimensional proton NMR studies of the conformations and orientations of n-alkanes in a liquid-crystal solvent}}}, doi = {{10.1021/j100117a037}}, volume = {{97}}, year = {{1993}}, } @article{40003, author = {{Kitzerow, Heinz-Siegfried and Crooker, P. P.}}, issn = {{0267-8292}}, journal = {{Liquid Crystals}}, keywords = {{Condensed Matter Physics, General Materials Science, General Chemistry}}, number = {{1}}, pages = {{31--43}}, publisher = {{Informa UK Limited}}, title = {{{Electric field effects on the droplet structure in polymer dispersed cholesteric liquid crystals}}}, doi = {{10.1080/02678299308029051}}, volume = {{13}}, year = {{1993}}, } @article{40005, author = {{Kitzerow, Heinz-Siegfried and Schmid, H. and Ranft, A. and Heppke, G. and Hikmet, R. A. M. and Lub, J.}}, issn = {{0267-8292}}, journal = {{Liquid Crystals}}, keywords = {{Condensed Matter Physics, General Materials Science, General Chemistry}}, number = {{3}}, pages = {{911--916}}, publisher = {{Informa UK Limited}}, title = {{{Observation of blue phases in chiral networks}}}, doi = {{10.1080/02678299308027768}}, volume = {{14}}, year = {{1993}}, } @article{40074, author = {{Dolganov, V. K. and Lourie, O. R. and Heppke, G. and Kitzerow, Heinz-Siegfried}}, issn = {{1155-4312}}, journal = {{Journal de Physique II}}, keywords = {{Physics and Astronomy (miscellaneous), General Engineering, Atomic and Molecular Physics, and Optics}}, number = {{7}}, pages = {{1087--1096}}, publisher = {{EDP Sciences}}, title = {{{Anomalies of the temperature dependence of electrostriction in blue phases}}}, doi = {{10.1051/jp2:1993185}}, volume = {{3}}, year = {{1993}}, } @article{40071, author = {{Kitzerow, Heinz-Siegfried and Crooker, P. P.}}, issn = {{1155-4312}}, journal = {{Journal de Physique II}}, keywords = {{Physics and Astronomy (miscellaneous), General Engineering, Atomic and Molecular Physics, and Optics}}, number = {{5}}, pages = {{719--726}}, publisher = {{EDP Sciences}}, title = {{{UV-cured cholesteric polymer-dispersed liquid crystal display}}}, doi = {{10.1051/jp2:1993162}}, volume = {{3}}, year = {{1993}}, } @inproceedings{40516, author = {{Molsen, H. and Bardon, R. and Kitzerow, Heinz-Siegfried}}, booktitle = {{SID Conference Proceedings, 13th International Display Research Conference}}, pages = {{113--116}}, publisher = {{Society for Information Display (SID)}}, title = {{{Electrooptics of Polymer-Dispersed Ferroelectric Liquid Crystals}}}, year = {{1993}}, } @article{40327, author = {{Heppke, G. and Kitzerow, Heinz-Siegfried and Molsen, H.}}, issn = {{1058-725X}}, journal = {{Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals}}, keywords = {{Condensed Matter Physics}}, number = {{1}}, pages = {{471--476}}, publisher = {{Informa UK Limited}}, title = {{{Electroclinic Effect in a Polymer-Dispersed Ferroelectric Liquid Crystal}}}, doi = {{10.1080/10587259308030159}}, volume = {{237}}, year = {{1993}}, } @article{40324, author = {{Krüerke, D. and Kitzerow, Heinz-Siegfried and Heppke, G. and Vill, V.}}, issn = {{0005-9021}}, journal = {{Berichte der Bunsengesellschaft für physikalische Chemie}}, keywords = {{General Chemical Engineering}}, number = {{10}}, pages = {{1371--1375}}, publisher = {{Wiley}}, title = {{{First Observation of Selective Reflection and Blue Phases in Chiral Discotic Liquid Crystals}}}, doi = {{10.1002/bbpc.19930971032}}, volume = {{97}}, year = {{1993}}, } @article{40326, author = {{Baena, Maria J. and Buey, Julio and Espinet, Pablo and Kitzerow, Heinz-Siegfried and Heppke, Gerd}}, issn = {{0570-0833}}, journal = {{Angewandte Chemie International Edition in English}}, keywords = {{General Chemistry, Catalysis}}, number = {{8}}, pages = {{1201--1203}}, publisher = {{Wiley}}, title = {{{Metallomesogens with a Cholesteric Mesophase}}}, doi = {{10.1002/anie.199312011}}, volume = {{32}}, year = {{1993}}, } @article{43449, abstract = {{We present subpicosecond time-resolved four-wave-mixing studies on GaAs/AlAs short-period superlattices having different miniband widths. Photon echoes are observed as a consequence of the inhomogeneous broadening of the excitonic resonance. In addition, the photon-echo signal exhibits periodic modulations as a function of the time delay between the excitation laser pulses. Free excitons and excitons bound to neutral acceptors are identified as the underlying three-level system leading to the observed photon-echo quantum beats. From the beat period we can directly infer the dissociation energy of the bound exciton. In accordance with theory, we find that the dissociation energy decreases with increasing miniband width, i.e., when the excitons become less confined. In addition, we find that the dephasing rate of bound excitons is about one order of magnitude less than that of free excitons and is mainly determined by energy relaxation.}}, author = {{Meier, Torsten and Koch, M. and Weber, D. and Feldmann, J. and Göbel, E.O. and Schulze, A. and Thomas, P. and Schmitt-Rink, S. and Ploog, K.}}, journal = {{Physical Review B}}, number = {{3}}, pages = {{1532--1539}}, publisher = {{American Physical Society}}, title = {{{Subpicosecond photon-echo spectroscopy on GaAs/AlAs short-period superlattices}}}, doi = {{10.1103/PhysRevB.47.1532}}, volume = {{47}}, year = {{1993}}, } @inbook{43442, abstract = {{Femtosecond nonlinear laser spectroscopy is applied to study the dynamics of coherent optical excitations in semiconductors. In particular, beat phenomena of excitonic excitations in quantum wells and superlattice structures will be considered. We will demonstrate that four wave mixing experiments with time resolved detection of the nonlinear signal are able to distinguish between quantum beats and polarization interference. In addition, we report for a GaAs/AlAs superlattice the observation of quantum beats in the photon echo signal. The occurence of these beats is attributed to the simultaneous excitation of bound and localized excitons.}}, author = {{Meier, Torsten and Göbel, E.O. and Koch, M. and Feldmann, J. and von Plessen, G. and Schulze, A. and Thomas, P. and Schmitt-Rink, S. and Köhler, K. and Ploog, K.}}, booktitle = {{Optical Phenomena in Semiconductor Structures of Reduced Dimension}}, editor = {{Lookwood, D. and Pinczuk, A.}}, isbn = {{978-94-010-4845-3}}, pages = {{145--155}}, publisher = {{Springer}}, title = {{{Time resolved Four Wave Mixing in GaAs/AlAs Quantum Well Structures}}}, doi = {{10.1007/978-94-011-1912-2_14}}, year = {{1993}}, } @article{43448, abstract = {{We report on the coherent dynamics of excitonic wave packets observed in transient four-wave mixing experiments on strained InGaAs/GaAs quantum-well structures. The excitonic noneigenstates are created by using laser pulses shorter than the electron round trip time within the exciton orbital. A characteristic temporal modulation of the diffracted signal is observed, which resembles the coherent dynamics of an electron wave packet in a hydrogen atom expected for the case of a simultaneous excitation of all bound and the lowest continuum states.}}, author = {{Meier, Torsten and Feldmann, J. and von Plessen, G. and Koch, M. and Göbel, E.O. and Thomas, P. and Bacher, G. and Hartmann, C. and Schweizer, H. and Schäfer, W. and Nickel, H.}}, journal = {{Physical review letters}}, number = {{20}}, pages = {{3027--3030}}, publisher = {{American Physical Society}}, title = {{{Coherent Dynamics of Excitonic Wave Packets}}}, doi = {{10.1103/PhysRevLett.70.3027}}, volume = {{70}}, year = {{1993}}, } @article{43447, abstract = {{Exciton coupling is studied for double quantum wells, which are separated by thick barriers. Results are presented for the linear optical spectrum, stationary and transient luminescence as well as four-wave-mixing signals. Additionally, coherent and incoherent transport through the barrier is considered}}, author = {{Meier, Torsten and Batsch, M. and Thomas, P. and Lindberg, M. and Koch, S.W. and Shah, J.}}, journal = {{Physical Review B}}, number = {{16}}, pages = {{11817--11826}}, publisher = {{American Physical Society}}, title = {{{Dipole-dipole coupling of excitons in double quantum wells}}}, doi = {{10.1103/PhysRevB.48.11817}}, volume = {{48}}, year = {{1993}}, } @inproceedings{44286, abstract = {{In degenerate four-wave-mixing (DFWM) experiments the polarization of the incident laser pulses can have a strong influence on the measured signal. For GaAs quantum wells a number of DFWM experiments were performed by using either parallel or perpendicular polarization of the incident laser pulses. Experimentally, it turned out that some characteristic features of the signal differ appreciably for the two configurations. In particular, different dephasing times, phase shifts of the quantum beats, different time-resolved behavior (echoes versus free-induction decay), and intensity dependence of the measured signal have been reported}}, author = {{Meier, Torsten and Bennhardt, D. and Thomas, P. and Eccleston, R. and Mayer, E. and Kuhl, J.}}, booktitle = {{Quantum Electronics and Laser Science Conference}}, isbn = {{1-55752-302-9}}, location = {{Baltimore, Maryland United States}}, title = {{{Theory for polarization-dependent four-wave-mixing signals in quantum wells}}}, year = {{1993}}, } @inproceedings{44287, abstract = {{We investigate the coherent coupling of free and bound excitonic transitions, as wets as of distinct excitonic transitions arising from spatially separated quantum-well islands by means of time-resolved four-wave-mixing experiments.}}, author = {{Meier, Torsten and Koch, M. and Feldmann, J. and von Plessen, G. and Schulze, A. and Göbel, E.O. and Thomas, P. and Schmitt-Rink, S. and Shah, J. and Ploog, K. and Köhler, K.}}, booktitle = {{Quantum Electronics and Laser Science Conference}}, isbn = {{1-55752-302-9}}, location = {{Baltimore, Maryland United States}}, title = {{{Coherent coupling of exciton transitions in semiconductor quantum structures}}}, year = {{1993}}, }