@inproceedings{4231, author = {{Lindner, Jörg}}, location = {{ Universidad Autónoma de Madrid (Spain)}}, title = {{{Characterisation of nanostructured materials for electronic and photonic information processing}}}, year = {{2009}}, } @inproceedings{4232, author = {{Lindner, Jörg}}, location = {{Bad Karlshafen (Germany)}}, title = {{{Ion Implantation: Fundamental Aspects and Recent Applications}}}, year = {{2009}}, } @inproceedings{4233, author = {{Lindner, Jörg}}, location = {{Bochum (Germany)}}, title = {{{Ionenstrahlmodifikation kleiner Oberflächenbereiche mittels selbstorganisierter Nanomasken}}}, year = {{2009}}, } @inproceedings{4234, author = {{Reichardt, F. and Weinl, M. and Gogel, D. and Wätje, K. and Wixforth, A. and Stritzker, B. and Lindner, Jörg}}, location = {{Straßburg (France)}}, title = {{{Synthesis of 2D-Nanostructured ZnO Thin Films using Nanosphere Lithography and Sputter Deposition}}}, year = {{2009}}, } @article{16111, author = {{Heim, B. and Elser, D. and Bartley, Tim and Sabuncu, M. and Wittmann, C. and Sych, D. and Marquardt, C. and Leuchs, G.}}, issn = {{0946-2171}}, journal = {{Applied Physics B}}, pages = {{635--640}}, title = {{{Atmospheric channel characteristics for quantum communication with continuous polarization variables}}}, doi = {{10.1007/s00340-009-3838-8}}, year = {{2009}}, } @article{3094, abstract = {{We demonstrate for the first time the feasibility of free space quantum key distribution with continuous variables under real atmospheric conditions. More specifically, we transmit coherent polarization states over a 100 m free space channel on the roof of our institute's building. In our scheme, signal and local oscillator (LO) are combined in a single spatial mode, which auto-compensates atmospheric fluctuations and results in an excellent interference. Furthermore, the LO acts as a spatial and spectral filter, thus allowing unrestrained daylight operation.}}, author = {{Elser, D. and Bartley, Tim and Heim, B. and Wittmann, Ch and Sych, D. and Leuchs, G.}}, issn = {{1367-2630}}, journal = {{New Journal of Physics}}, number = {{4}}, pages = {{045014}}, title = {{{Feasibility of free space quantum key distribution with coherent polarization states}}}, year = {{2009}}, } @inproceedings{4218, abstract = {{In this work we focus on the fabrication of ohmic contacts and of Schottky barrier devices (SBD) on non-polar cubic GaN epilayers grown by molecular beam epitaxy (MBE). A Ti/Al/Ni/Au metallization was used for ohmic contacts and the contact resistance was measured by transmission line measurements (TLM). Ni, Pd, Ag and NiSi Schottky barrier devices 300 µm in diameter were fabricated by thermal evaporation using contact lithography on cubic GaN epilayers. The current-voltage (I-V) and the capacity-voltage (C-V) characteristics were studied at room temperature in detail. A clear rectifying behavior was measured in all SBDs. In the Ni and Ag SBDs an abnormal large leakage current under reverse bias was observed. Isochronal thermal annealing of these Ni and Ag based SBDs at 200°C in air improved the reverse characteristics by up to three orders of magnitude. This is in contrast to the Pd contacts, where the as grown contact showed already good performance and thermal annealing had nearly no influence on the I-V characteristics. For all SBDs the magnitude of the reverse current is generally larger than that expected due to thermionic emission and an exponential increase of the reverse current is observed with increasing reverse voltage. In-depth analysis of the I-V characteristic showed that a thin surface barrier is formed at the metal semiconductor interface and that crystal defects like dislocations may be the reasons for the discrepancy between experimental data and thermionic emission theory. }}, author = {{As, Donat J. and Tschumak, Elena and Laubenstein, Irina and Kemper, Ricarda M. and Lischka, Klaus}}, booktitle = {{Materials Research Society Symposium Proceedings}}, pages = {{3--8}}, publisher = {{Materials Research Society}}, title = {{{Schottky and Ohmic Contacts on Non-Polar Cubic GaN Epilayers}}}, doi = {{10.1557/proc-1108-a01-02}}, volume = {{1108}}, year = {{2009}}, } @article{29678, author = {{Ksenzov, D. and Grigorian, S. and Hendel, S. and Bienert, F. and Sacher, Marc and Heinzmann, U. and Pietsch, U.}}, issn = {{1862-6300}}, journal = {{physica status solidi (a)}}, keywords = {{Materials Chemistry, Electrical and Electronic Engineering, Surfaces, Coatings and Films, Surfaces and Interfaces, Condensed Matter Physics, Electronic, Optical and Magnetic Materials}}, number = {{8}}, pages = {{1875--1879}}, publisher = {{Wiley}}, title = {{{Reflection of femtosecond pulses from soft X-ray free-electron laser by periodical multilayers}}}, doi = {{10.1002/pssa.200881585}}, volume = {{206}}, year = {{2009}}, } @article{40201, author = {{Andersen, U.L. and Leuchs, G. and Silberhorn, Christine}}, issn = {{1863-8880}}, journal = {{Laser & Photonics Reviews}}, keywords = {{Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials}}, number = {{3}}, pages = {{337--354}}, publisher = {{Wiley}}, title = {{{Continuous-variable quantum information processing}}}, doi = {{10.1002/lpor.200910010}}, volume = {{4}}, year = {{2009}}, } @inproceedings{44108, author = {{Meier, Torsten and Zhang, Tianhao and Kuznetsova, Irina and Yang, Lijun and Bristow, Alan D and Dai, Xingcan and Li, Xiaoqin and Thomas, P. and Mukamel, S. and Mirin, Richard P. and Cundiff, S.T.}}, booktitle = {{Ultrafast Phenomena XVI: Proceedings of the 16th International Conference, Palazzo dei Congressi Stresa, Italy, June 9--13, 2008}}, location = {{Palazzo dei Congressi Stresa, Italy}}, pages = {{247--249}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Ultrafast Coherent Interactions in Quantum Wells Studied by Two-Dimensional Fourier Transform Spectroscopy}}}, year = {{2009}}, } @article{44107, abstract = {{We demonstrate a technique for the generation and detection of electron currents at surfaces on a femtosecond time scale with a contact-free experimental setup based on a combination of coherent control and photoemission spectroscopy. We have applied this technique for electrons excited into image-potential states on a Cu(100) surface that form a free-electron-like band in the direction parallel to the surface. The photogeneration of currents is described by optical Bloch equations for a multiband model. By incorporating field-induced interband and intersubband transitions together with intraband accelerations into the model, the observed phase dependence of the population and of the current can be reproduced.}}, author = {{Meier, Torsten and Güdde, Jens and Rohleder, M. and Koch, S.W. and Höfer, Ulrich}}, journal = {{physica status solidi c}}, number = {{2}}, pages = {{461--465}}, publisher = {{WILEY‐VCH Verlag}}, title = {{{Generation and time‐resolved detection of coherently controlled electric currents at surfaces}}}, doi = {{10.1002/pssc.200880350}}, volume = {{6}}, year = {{2009}}, } @inproceedings{4179, abstract = {{We numerically investigate Whispering Gallery Modes (WGM) in a subwavelength microdisk resonator [1] embedded in an uniaxial anisotropic liquid crystal environment. It is shown that the WGMs have anticrossing behavior when modes of different radial mode order M or azimuthal order N approach each other spectrally. }}, author = {{Förstner, Jens and Declair, S. and Meier, Cedrik and Meier, Torsten}}, booktitle = {{Theoretical and Computational Nanophotonics Tacona-Photonics}}, keywords = {{tet_topic_microdisk}}, location = {{Tacona}}, number = {{1}}, pages = {{60--62}}, title = {{{Anticrossing of Whispering Gallery Modes in Microdisk Resonators Embedded in a Liquid Crystal}}}, doi = {{10.1063/1.3253921}}, volume = {{1176}}, year = {{2009}}, } @inproceedings{44069, abstract = {{Recently it has been shown experimentally that it is possible to coherently control nano-optical excitations by using sophisticated shaped laser pulses. In this work a similar technique is used to theoretically investigate a hybrid nanostructure which consists of a metal aperture and a quantum wire. It is shown that one can concentrate the optically excited electron density at an arbitrary position due to wave packet dynamics by chosing particular frequency components and phases of the chirped laser pulse. The optimization process is performed with a genetic algorithm which is linked to a 3D-FDTD solver.}}, author = {{Meier, Torsten and Reichelt, Matthias}}, booktitle = {{DPG Spring meeting 2009}}, issn = {{0420-0195}}, location = {{Dresden, Germany}}, number = {{5}}, title = {{{Coherent control in hybrid metal-semiconductor nanostructures}}}, volume = {{44}}, year = {{2009}}, } @article{23481, abstract = {{A one-dimensional semiconductor nanostructure is locally excited through a metal aperture. It is shown that the electron density can be coherently localized at desired spatial and temporal positions by using nontrivially shaped laser pulses. To obtain the optimized laser field, Bloch equations for a tight-binding model system are solved together with a genetic pulse-shaping algorithm. Full three-dimensional finite-difference time-domain (FDTD) simulations of the Maxwell–Bloch equations confirm the predicted coherent spatiotemporal control.}}, author = {{Reichelt, Matthias and Meier, Torsten}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{19}}, pages = {{2900--2902}}, title = {{{Shaping the spatiotemporal dynamics of the electron density in a hybrid metal-semiconductor nanostructure}}}, doi = {{10.1364/ol.34.002900}}, volume = {{34}}, year = {{2009}}, } @inproceedings{4184, abstract = {{We have experimentally investigated injection currents generated by all-optical excitation of GaAs/AlGaAs quantum wells excited with 130 fs optical pulses. The currents have been detected via free-space THz experiments at room temperature. Our experiments prove that Coulomb effects strongly influence injection currents. This becomes most prominently visible when exciting light-hole exciton transitions. At this photon energy we observe a pronounced phase shift of the current transients which is due to oppositely oriented heavy-hole and light-hole type contributions. We are currently developing a microscopic theory based on a 14×14 k.p model in combination with the semiconductor Bloch equations to describe the observed features quantitatively. The combined theoretical and experimental approach will allow us to analyze the influence of the bandstructure and interaction effects on the injection current amplitude and current dynamics.}}, author = {{Bieler, M. and Pierz, K. and Siegner, U. and Dawson, P. and Duc, H. T. and Förstner, Jens and Meier, Torsten}}, booktitle = {{Ultrafast Phenomena in Semiconductors and Nanostructure Materials XIII}}, editor = {{Tsen, Kong-Thon and Song, Jin-Joo and Betz, Markus and Elezzabi, Abdulhakem Y.}}, keywords = {{tet_topic_qw}}, location = {{San Jose (California / USA)}}, pages = {{721404--721404--13}}, publisher = {{SPIE}}, title = {{{Generation of injection currents in (110)-oriented GaAs quantum wells: experimental observation and development of a microscopic theory}}}, doi = {{10.1117/12.811841}}, volume = {{7214}}, year = {{2009}}, } @inproceedings{44104, abstract = {{The paper presents a theoretical analysis of the nonlinear THz response from the internal transitions of coherent and incoherent excitons based on the formulated microscopic THz theory. Moreover, the response of unexcited semiconductors to extremely intense THz fields is investigated .The intersubband transitions of optically excited quantum wells using linear THz spectroscopy is also studied. The computed differential transmission shows a characteristic Fano-like line shape of the intersubband resonance. The pure intersubband contribution is given by a simple Lorentzian. Applying the microscopic theory, the Fano features of the total response can be attributed to the phase-sensitive superposition of the intersubband transitions and the ponderomotive contribution. These results are in excellent agreement with recent experiments.}}, author = {{Meier, Torsten and Koch, S.W. and Kira, M. and Steiner, J.T. and Golde, D.}}, booktitle = {{ CLEO/Europe - EQEC 2009 - European Conference on Lasers and Electro-Optics and the European Quantum Electronics Conference}}, isbn = {{978-1-4244-4079-5}}, location = {{Munich, Germany}}, publisher = {{IEEE}}, title = {{{Microscopic theory of the linear and nonlinear Terahertz response of semiconductors}}}, doi = {{10.1109/CLEOE-EQEC.2009.5192555}}, year = {{2009}}, } @inproceedings{44105, abstract = {{By combining coherent control schemes and photoelectron spectroscopy it is possible to generate ultrafast current pulses at surfaces and in solids and to detect their decay directly in momentum space with femtosecond time resolution.}}, author = {{Meier, Torsten and Koch, S.W. and Rohleder, M. and Gudde, J. and Hofer, U.}}, booktitle = {{Conference on Lasers and Electro-Optics and 2009 Conference on Quantum electronics and Laser Science Conference}}, issn = {{2160-9004}}, location = {{Baltimore, MD, USA}}, pages = {{1--2}}, publisher = {{IEEE}}, title = {{{Ultrafast coherent photoelectron emission effects and their application for time-domain studies of current transport}}}, doi = {{10.1364/IQEC.2009.IThI5}}, year = {{2009}}, } @article{24983, abstract = {{The recently developed two-dimensional Fourier-Transform-Spectroscopy (2DFTS) in the optical regime has been established as an elegant experiment, which has manifold of applications in the investigation of semiconductor nanostructures. Here we focus on the real and imaginary part 2DFT spectra. As predicted recently, using rephasing and non-rephasing modes, we are able to determine the homogeneous and inhomogeneous broadenings of coupled excitonic resonances even for weak disorder where photon-echo data are not useful. Computed real and imaginary parts of the 2DFTS for rephasing and non-rephasing modes are compared with experimental data of a GaAs quantum well. It is demonstrated, that phase sensitive data for the rephasing and non-rephasing modes are able to accurately provide the disorder induced broadening in a complex coupled system for each transition separately. }}, author = {{Kuznetsova, Irina and Thomas, Peter and Meier, Torsten and Zhang, Tianhao and Cundiff, Steven T.}}, issn = {{1610-1634}}, journal = {{physica status solidi (c)}}, number = {{2}}, pages = {{445--448}}, publisher = {{WILEY‐VCH Verlag}}, title = {{{Determination of homogeneous and inhomogeneous broadenings of quantum-well excitons by 2DFTS: An experiment-theory comparison}}}, doi = {{10.1002/pssc.200880302}}, volume = {{6}}, year = {{2009}}, } @article{24982, abstract = {{A microscopic analysis of the emitted radiation of a semiconductor nanostructure after excitation with an extremely intense ultrashort laser pulse is presented. It is shown that the extreme nonlinear optical response is not sufficiently described by pure interband transitions but one has to include intraband effects as well. Numerical solutions of extended Bloch equations that include the coupled inter- and intraband dynamics are presented. For large excitation intensities, the intraband effects strongly modify the polarization dynamics and lead to a strong enhancement of high-harmonic generation compared to pure interband dynamics.}}, author = {{Golde, Daniel and Meier, Torsten and Koch, Stephan W.}}, issn = {{1610-1634}}, journal = {{physica status solidi (c)}}, number = {{2}}, pages = {{420--423}}, publisher = {{WILEY‐VCH Verlag}}, title = {{{Microscopic analysis of high-harmonic generation in semiconductor nanostructures}}}, doi = {{10.1002/pssc.200880309}}, volume = {{6}}, year = {{2009}}, } @article{44106, author = {{Meier, Torsten and Michler, Peter}}, journal = {{physica status solidi c}}, number = {{2}}, pages = {{379--380}}, publisher = {{WILEY‐VCH Verlag}}, title = {{{Preface}}}, doi = {{10.1002/pssc.200960045}}, volume = {{6}}, year = {{2009}}, }