@article{43304, abstract = {{The coherent dynamics of magnetoexcitons in semiconductor nanorings following pulsed optical excitation is studied. The calculated temporal evolution of the excitonic dipole moment may be understood as a superposition of the relative motion of electrons and holes and a global circular motion associated with the magnetic-field splitting of these states. This dynamics of the electron-hole pairs can be generated either by local optical excitation of an ordered ring or, alternatively, by homogeneous excitation of rings with broken rotational symmetry due to disorder or band tilting.}}, author = {{Meier, Torsten and Maschke, K. and Thomas, P. and Koch, S.W.}}, journal = {{The European Physical Journal B - Condensed Matter and Complex Systems}}, pages = {{599--606}}, publisher = {{EDP Sciences, Springer-Verlag}}, title = {{{Coherent Dynamics of Magnetoexcitons in Semiconductor Nanorings}}}, doi = {{10.1007/s100510170305}}, volume = {{19}}, year = {{2001}}, } @inproceedings{43614, abstract = {{The dynamics of optically generated electron-hole pairs is investigated in a disordered semiconductor nanowire. The particle pairs are generated by short laser pulses and their dynamics is followed using the Heisenberg equation of motion. Is is shown that Coulomb-correlation acts against localization in the case of the two-interacting particles (TIP) problem. Furthermore, currents are generated using a coherent combination of full-gap and half-gap pulses. The subsequent application of a full-gap pulse after time τ produces an intraband echo phenomenon 2τ time later. The echo current is shown to depend on the mass ratio between the electrons and the holes.}}, author = {{Meier, Torsten and Varga, I. and Schlichenmaier, C. and Maschke, K. and Thomas, P. and Koch, S.W.}}, booktitle = {{Proceedings of the XXXVIth Rencontres de Moriond on Electronic Correlations: From Meso-Physics to Nano-Physics}}, editor = {{Martin, Thierry and Tran Thanh Van, J. and Montambaux, Gilles}}, location = {{Les Arcs, France}}, pages = {{343--347}}, publisher = {{EDP Sciences}}, title = {{{Dynamics of Coulomb-correlated electron-hole pairs in disordered semiconductor nanowires}}}, doi = {{10.48550/arXiv.cond-mat/0111452}}, year = {{2001}}, } @article{43308, abstract = {{A microscopic many-body theory for the optical and electronic properties of semiconductors is reviewed with an emphasis on the role of correlation effects. At the semiclassical level, the semiconductor Bloch equations include many-body effects via bandgap and field renormalization as well as correlation contributions representing two electron-hole pair amplitudes, excitonic populations, and coupled interband and intraband coherences. These Coulomb interaction induced carrier correlations lead to characteristic signatures in nonlinear semiconductor spectroscopy. At the fully quantum mechanical level the dominant light-matter correlations are described by coupled semiconductor Bloch and luminescence equations. Excitonic emission properties of quantum well and microcavity systems are discussed, including effects such as coherent signatures in the secondary emission and coherent control of the emitted light.}}, author = {{Meier, Torsten and Kira, M. and Koch, S.W.}}, journal = {{Journal of Optics B: Quantum and Semiclassical Optics}}, number = {{5}}, publisher = {{IOP Publishing}}, title = {{{Correlation effects in the excitonic optical properties of semiconductors}}}, doi = {{10.1088/1464-4266/3/5/201}}, volume = {{3}}, year = {{2001}}, } @article{43309, abstract = {{The nonlinear optical response of a ZnSe single quantum well is investigated by spectrally resolving a wave-mixing signal using a three-beam configuration. A delayed third pulse with direction k3 leads to coherent oscillations in the spectrum emitted in 2k2–k1. Polarization-dependent measurements highlight the importance of higher-order Coulomb correlations as the dominant coupling mechanism between the three pulses. The experimental results are well explained by microscopic calculations including four-particle correlations up to fifth order in the fields.}}, author = {{Meier, Torsten and Wagner, H.P. and Tranitz, H.-P. and Reichelt, Matthias and Koch, S.W.}}, journal = {{Physical Review B}}, number = {{23}}, publisher = {{American Physical Society}}, title = {{{Coherent spectral oscillations in multiwave mixing}}}, doi = {{10.1103/PhysRevB.64.233303}}, volume = {{64}}, year = {{2001}}, } @inproceedings{44129, abstract = {{Summary form only given. Since the original discovery of the excitonic optical Stark effect, substantial progress has been made in the understanding of this ultrafast nonlinear optical effect. Recently, a red shift of the excitonic absorption line has been reported using low intensity excitation detuned 4.5 meV below the 1s-heavy-hole (hh) resonance and cross-circularly-polarized pulses. This was attributed to higher-order Coulomb correlations, interpretable as bound and unbound two-exciton states and memory effects. For co-circularly polarized pulses the well-known blue shift was found. Here we present a related effect occurring in the higher-intensity regime. Standard pump-probe experiments were performed on high-quality 8.5 nm-thick In/sub 0.04/Ga/sub 0.96/As multiple quantum well (MQW) samples.}}, author = {{Meier, Torsten and Chatterjee, S. and Brick, P. and Ell, C. and Gibbs, H.M. and Khitrova, G. and Sieh, C. and Koch, S.W.}}, booktitle = {{Coherent optical nonlinearities in normal mode microcavities}}, isbn = {{1-55752-663-X}}, location = {{Baltimore, MD, USA}}, pages = {{196--197}}, publisher = {{Optical Society of America}}, title = {{{The excitonic Stark effect: Absorption splitting and the influence of the light-hole exciton}}}, doi = {{10.1109/QELS.2001.962058}}, year = {{2001}}, } @inproceedings{44128, abstract = {{Summary form only given. When a quantum-well exciton transition is resonant with a single mode of a high-Q microcavity the linear reponse of the coupled system may be described in terms of normal modes ("cavity polaritons"), which arise as a result of the interplay of absorption and dispersion of the exciton transition within the cavity. The nonlinear response of these systems has often been discussed in terms of "polaritonic nonlinearities". It is desirable to investigate the nonlinearities of normal-mode microcavities (NMC's) at the same level and to determine if the microscopic theory accounting for the bare-QW response also quantitatively accounts for the normal-mode nonlinear response. We report here an extensive series of pump-probe experiments, investigating the time-resolved reflectivity of an NMC as a function of pump and probe polarization and pump fluence.}}, author = {{Meier, Torsten and Lee, Y-.S and Norris, T.B. and Khitrova, G. and Gibbs, H.M. and Sieh, C. and Koch, S.W. and Jahnke, F.}}, booktitle = {{Quantum Electronics and Laser Science Conference}}, isbn = {{1-55752-663-X}}, location = {{Baltimore, MD, USA}}, pages = {{230--231}}, publisher = {{Optical Society of America}}, title = {{{Coherent optical nonlinearities in normal mode microcavities}}}, doi = {{10.1109/QELS.2001.962141}}, year = {{2001}}, } @inproceedings{44130, abstract = {{Summary form only given. Optical and electronic properties of semiconductor heterostructures are strongly influenced by inherent disorder effects. The disorder consists of alloy disorder in ternary or quaternary compound semiconductors and interface roughness in semiconductor quantum wells. The spatial scales of disorder depend on the growth process. The disorder scale has up to now been extremely difficult to determine by macroscopic optical experiments. Here, we use excitons and biexcitons as mesoscopic probes in coherent excitation spectroscopy (CES) to reveal the spatial scale of disorder.}}, author = {{Meier, Torsten and Finger, E. and Kraft, S. and Hofmann, M. and Nau, S. and Bernatz, G. and Stolz, W. and Thomas, P. and Koch, S.W. and Rühle, W.W.}}, booktitle = {{Quantum Electronics and Laser Science Conference}}, isbn = {{1-55752-663-X}}, location = {{Baltimore, MD, USA}}, pages = {{269}}, publisher = {{Optical Society of America}}, title = {{{Excitons and biexcitons as mesoscopic probes of disorder in semiconductor heterostructures}}}, doi = {{10.1109/QELS.2001.962232}}, year = {{2001}}, } @article{13751, author = {{Esser, N. and Schmidt, Wolf Gero and Cobet, C. and Fleischer, K. and Shkrebtii, A. I. and Fimland, B. O. and Richter, W.}}, issn = {{0734-211X}}, journal = {{Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures}}, number = {{5}}, title = {{{Atomic structure and optical anisotropy of III–V(001) surfaces}}}, doi = {{10.1116/1.1394730}}, volume = {{19}}, year = {{2001}}, } @article{13753, author = {{Pulci, O. and Schmidt, Wolf Gero and Bechstedt, F.}}, issn = {{0031-8965}}, journal = {{physica status solidi (a)}}, number = {{1}}, pages = {{105--110}}, title = {{{Structure and Energetics of P-rich GaP(001) Surfaces}}}, doi = {{10.1002/1521-396x(200103)184:1<105::aid-pssa105>3.0.co;2-d}}, volume = {{184}}, year = {{2001}}, } @article{13847, author = {{Hingerl, K and Balderas-Navarro, R.E and Bonanni, A and Tichopadek, P and Schmidt, Wolf Gero}}, issn = {{0169-4332}}, journal = {{Applied Surface Science}}, pages = {{769--776}}, title = {{{On the origin of resonance features in reflectance difference data of silicon}}}, doi = {{10.1016/s0169-4332(01)00114-3}}, volume = {{175-176}}, year = {{2001}}, } @article{13849, author = {{Schmidt, Wolf Gero and Bechstedt, F. and Bernholc, J.}}, issn = {{0163-1829}}, journal = {{Physical Review B}}, title = {{{Terrace and step contributions to the optical anisotropy of Si(001) surfaces}}}, doi = {{10.1103/physrevb.63.045322}}, volume = {{63}}, year = {{2001}}, } @article{27987, author = {{Buyken, Anette and Toeller, M and Heitkamp, G and Irsigler, K and Holler, C and Santeusanio, F and Stehle, P and Fuller, JH}}, issn = {{0742-3071}}, journal = {{Diabet Med}}, number = {{5}}, pages = {{351--359}}, title = {{{Carbohydrate sources and glycaemic control in Type 1 diabetes mellitus. EURODIAB IDDM Complications Study Group.}}}, doi = {{10.1046/j.1464-5491.2000.00283.x}}, volume = {{17}}, year = {{2000}}, } @article{7690, author = {{Heidtkamp, C. and Meier, Cedrik and Reuter, D. and Versen, M. and Hoch, S. and Diaconescu, D. and Wieck, A.D.}}, issn = {{0921-4526}}, journal = {{Physica B: Condensed Matter}}, pages = {{1728--1729}}, publisher = {{Elsevier BV}}, title = {{{Tunable backscattering in quantum Hall systems induced by neighbouring gates}}}, doi = {{10.1016/s0921-4526(99)02892-6}}, volume = {{284-288}}, year = {{2000}}, } @article{7691, author = {{Diaconescu, Dorina and Hoch, Sascha and Heidtkamp, Christian and Meier, Cedrik and Reuter, Dirk and Wieck, Andreas D}}, issn = {{0921-4526}}, journal = {{Physica B: Condensed Matter}}, pages = {{1906--1907}}, publisher = {{Elsevier BV}}, title = {{{A new peak in the bend resistance of a four-terminal device written by FIB implantation}}}, doi = {{10.1016/s0921-4526(99)03002-1}}, volume = {{284-288}}, year = {{2000}}, } @inproceedings{7692, author = {{Reuter, D. and Meier, Cedrik and Alvarez, M. A. and Koch, J. and Wieck, A. D.}}, booktitle = {{IECON Proc. }}, pages = {{1878}}, title = {{{Laterally resolved doping by focused ion beam implantation}}}, year = {{2000}}, } @article{35366, author = {{Quijada-Garrido, Isabel and Siebert, Hartmut and Friedrich, Christian and Schmidt, Claudia}}, issn = {{0024-9297}}, journal = {{Macromolecules}}, keywords = {{Materials Chemistry, Inorganic Chemistry, Polymers and Plastics, Organic Chemistry}}, number = {{10}}, pages = {{3844--3854}}, publisher = {{American Chemical Society (ACS)}}, title = {{{Flow Behavior of Two Side-Chain Liquid Crystal Polymers Studied by Transient Rheology}}}, doi = {{10.1021/ma991490m}}, volume = {{33}}, year = {{2000}}, } @inbook{35357, author = {{Mueller, Christian and Schmidt, Claudia and Koopmann, Florian and Frey, Holger}}, booktitle = {{Organosilicon Chemistry}}, publisher = {{Wiley-VCH Verlag GmbH}}, title = {{{Polymorphism and Molecular Mobility of Poly(silane)s and Poly(silylenemethlene)s}}}, doi = {{10.1002/9783527620777.ch95c}}, year = {{2000}}, } @article{27935, author = {{Bigga, Regine}}, journal = {{awt-info }}, pages = {{20--28}}, title = {{{Fünf vor zwölf und keinen Ausbildungsplatz. Eine Unterrichtsskizze zur Berufsorientierung. }}}, volume = {{2}}, year = {{2000}}, } @article{40084, author = {{Röder, Th. and Paelke, L. and Held, N. and Vinzelberg, S. and Kitzerow, Heinz-Siegfried}}, issn = {{0034-6748}}, journal = {{Review of Scientific Instruments}}, keywords = {{Instrumentation}}, number = {{7}}, pages = {{2759--2764}}, publisher = {{AIP Publishing}}, title = {{{Imaging of liquid crystals using a new scanning near-field optical microscope with microfabricated tips and shear force detection}}}, doi = {{10.1063/1.1150688}}, volume = {{71}}, year = {{2000}}, } @article{40083, author = {{Glossmann, Jochen and Hoischen, Andreas and Roder, Thorsten and Kitzerow, Heinz-Siegfried}}, issn = {{0015-0193}}, journal = {{Ferroelectrics}}, keywords = {{Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{1}}, pages = {{95--106}}, publisher = {{Informa UK Limited}}, title = {{{Asymmetric switching and storage effects in ferroelectric and antiferroelectric gels and polymers}}}, doi = {{10.1080/00150190008008011}}, volume = {{243}}, year = {{2000}}, }