@article{13658, author = {{Passmann, Regina and Favero, Priscila and Schmidt, Wolf Gero and Miotto, Ronei and Braun, Walter and Richter, Wolfgang and Kneissl, Michael and Esser, Norbert and Vogt, Patrick}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{12}}, title = {{{Adsorption structure of cyclopentene on InP(001)(2×4)}}}, doi = {{10.1103/physrevb.80.125303}}, volume = {{80}}, year = {{2009}}, } @article{13657, author = {{Sanna, Simone and Schmidt, Wolf Gero and Frauenheim, Th. and Gerstmann, Uwe}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{10}}, title = {{{Rare-earth defect pairs in GaN: LDA+U calculations}}}, doi = {{10.1103/physrevb.80.104120}}, volume = {{80}}, year = {{2009}}, } @article{13655, author = {{Thissen, P. and Grundmeier, Guido and Wippermann, S. and Schmidt, Wolf Gero}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{24}}, title = {{{Water adsorption on the α-Al2O3(0001) surface}}}, doi = {{10.1103/physrevb.80.245403}}, volume = {{80}}, year = {{2009}}, } @article{13802, author = {{Giannozzi, Paolo and Baroni, Stefano and Bonini, Nicola and Calandra, Matteo and Car, Roberto and Cavazzoni, Carlo and Ceresoli, Davide and Chiarotti, Guido L and Cococcioni, Matteo and Dabo, Ismaila and Dal Corso, Andrea and de Gironcoli, Stefano and Fabris, Stefano and Fratesi, Guido and Gebauer, Ralph and Gerstmann, Uwe and Gougoussis, Christos and Kokalj, Anton and Lazzeri, Michele and Martin-Samos, Layla and Marzari, Nicola and Mauri, Francesco and Mazzarello, Riccardo and Paolini, Stefano and Pasquarello, Alfredo and Paulatto, Lorenzo and Sbraccia, Carlo and Scandolo, Sandro and Sclauzero, Gabriele and Seitsonen, Ari P and Smogunov, Alexander and Umari, Paolo and Wentzcovitch, Renata M}}, issn = {{0953-8984}}, journal = {{Journal of Physics: Condensed Matter}}, number = {{39}}, title = {{{QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials}}}, doi = {{10.1088/0953-8984/21/39/395502}}, volume = {{21}}, year = {{2009}}, } @article{13844, abstract = {{EPR and ESE in nitrogen doped 4H- and 6H-SiC show besides the well known triplet lines of 14N on quasi-cubic (Nc,k) and hexagonal (Nc,h) sites additional lines (Nx) of comparatively low intensity providing half the hf splitting of Nc,k. Frequently re-interpreted as spin-forbid¬den lines, arising from Nc,k pairs and triads or resulting from hopping conductivity, only re¬cent¬ly the theoretical calculation of the corresponding g-tensors lead to a tentative model of distant NC donor pairs on inequivalent lattice sites which are coupled to S = 1 assuming a fine-struc¬ture splitting too small to be observed in the EPR and ESE experiments. In this work, we pre¬sent ESE nutation measurements confirming S = 1 for the Nx center. Analysing the nutation frequencies in comparison with that of the Nc,k (S = 1/2) spectrum as well as the line width of ESE and EPR spectra we obtain a rough estimate between 5104 cm-1 and 50104 cm-1 for the fine-structure splitting demonstrating efficient spin-coupling between nitrogen donors in 4H-SiC.}}, author = {{Savchenko, D.V. and Pöppl, Andreas and Kalabukhova, Ekaterina N. and Greulich-Weber, Siegmund and Rauls, Eva and Schmidt, Wolf Gero and Gerstmann, Uwe}}, issn = {{1662-9752}}, journal = {{Materials Science Forum}}, pages = {{343--346}}, title = {{{Spin-Coupling in Heavily Nitrogen-Doped 4H-SiC}}}, doi = {{10.4028/www.scientific.net/msf.615-617.343}}, volume = {{615-617}}, year = {{2009}}, } @article{18632, abstract = {{We present measurements of the effective electron mass in biaxial tensile strained silicon on insulator (SSOI) material with 1.2 GPa stress and in unstrained SOI. Hall-bar metal oxide semiconductor field effect transistors on 60 nm SSOI and SOI were fabricated and Shubnikov–de Haas oscillations in the temperature range of T=0.4–4 K for magnetic fields of B=0–10 T were measured. The effective electron mass in SSOI and SOI samples was determined as mt=(0.20±0.01)m0. This result is in excellent agreement with first-principles calculations of the effective electron mass in the presence of strain.}}, author = {{Feste, Sebastian F. and Schäpers, Thomas and Buca, Dan and Zhao, Qing Tai and Knoch, Joachim and Bouhassoune, Mohammed and Schindlmayr, Arno and Mantl, Siegfried}}, issn = {{1077-3118}}, journal = {{Applied Physics Letters}}, number = {{18}}, publisher = {{American Institute of Physics}}, title = {{{Measurement of effective electron mass in biaxial tensile strained silicon on insulator}}}, doi = {{10.1063/1.3254330}}, volume = {{95}}, year = {{2009}}, } @inproceedings{18634, abstract = {{A computational method to obtain optical conductivities from first principles is presented. It exploits a relation between the conductivity and the complex dielectric function, which is constructed from the full electronic band structure within the random-phase approximation. In contrast to the Drude model, no empirical parameters are used. As interband transitions as well as local-field effects are properly included, the calculated spectra are valid over a wide frequency range. As an illustration I present quantitative results for selected simple metals, noble metals, and ferromagnetic transition metals. The implementation is based on the full-potential linearized augmented-plane-wave method.}}, author = {{Schindlmayr, Arno}}, booktitle = {{Theoretical and Computational Nanophotonics: Proceedings of the 2nd International Workshop}}, editor = {{Chigrin, Dmitry N.}}, isbn = {{978-0-7354-0715-2}}, issn = {{1551-7616}}, location = {{Bad Honnef}}, number = {{1}}, pages = {{157--159}}, publisher = {{American Institute of Physics}}, title = {{{Optical conductivity of metals from first principles}}}, doi = {{10.1063/1.3253897}}, volume = {{1176}}, year = {{2009}}, } @article{18636, abstract = {{We derive formulas for the Coulomb matrix within the full-potential linearized augmented-plane-wave (FLAPW) method. The Coulomb matrix is a central ingredient in implementations of many-body perturbation theory, such as the Hartree–Fock and GW approximations for the electronic self-energy or the random-phase approximation for the dielectric function. It is represented in the mixed product basis, which combines numerical muffin-tin functions and interstitial plane waves constructed from products of FLAPW basis functions. The interstitial plane waves are here expanded with the Rayleigh formula. The resulting algorithm is very efficient in terms of both computational cost and accuracy and is superior to an implementation with the Fourier transform of the step function. In order to allow an analytic treatment of the divergence at k=0 in reciprocal space, we expand the Coulomb matrix analytically around this point without resorting to a projection onto plane waves. Without additional approximations, we then apply a basis transformation that diagonalizes the Coulomb matrix and confines the divergence to a single eigenvalue. At the same time, response matrices like the dielectric function separate into head, wings, and body with the same mathematical properties as in a plane-wave basis. As an illustration we apply the formulas to electron-energy-loss spectra (EELS) for nickel at different k vectors including k=0. The convergence of the spectra towards the result at k=0 is clearly seen. Our all-electron treatment also allows to include transitions from 3s and 3p core states in the EELS spectrum that give rise to a shallow peak at high energies and lead to good agreement with experiment.}}, author = {{Friedrich, Christoph and Schindlmayr, Arno and Blügel, Stefan}}, issn = {{0010-4655}}, journal = {{Computer Physics Communications}}, number = {{3}}, pages = {{347--359}}, publisher = {{Elsevier}}, title = {{{Efficient calculation of the Coulomb matrix and its expansion around k=0 within the FLAPW method}}}, doi = {{10.1016/j.cpc.2008.10.009}}, volume = {{180}}, year = {{2009}}, } @inproceedings{4181, abstract = {{We experimentally and theoretically investigate microdisk resonators with embedded quantum dots immersed in a liquid crystal in its nematic phase, showing the tunabililty of the photonic modes via external parameters like temperature or electric field.}}, author = {{Förstner, Jens and Meier, Cedrik and Piegdon, Karoline and Declair, Stefan and Hoischen, Andreas and Urbanski, Mark and Meier, Torsten and Kitzerow, Heinz-Siegfried}}, booktitle = {{Advances in Optical Sciences Congress}}, isbn = {{9781557528735}}, keywords = {{tet_topic_microdisk}}, location = {{Honolulu, Hawaii United States}}, publisher = {{OSA Technical Digest (CD) (Optical Society of America, 2009), paper NTuC2}}, title = {{{Coupling Dynamics of Quantum Dots in a Liquid-Crystal-Tunable Microdisk Resonator}}}, doi = {{10.1364/nlo.2009.ntuc2}}, year = {{2009}}, } @inproceedings{7642, author = {{Piegdon, Karoline A. and Matthias, Heinrich and Meier, Cedrik and Kitzerow, Heinz-Siegfried}}, booktitle = {{Emerging Liquid Crystal Technologies III}}, editor = {{Chien, Liang-Chy}}, publisher = {{SPIE}}, title = {{{Tunable optical properties of photonic crystals and semiconductor microdisks using liquid crystals}}}, doi = {{10.1117/12.774194}}, year = {{2008}}, } @inproceedings{52647, author = {{Gausemeier, Jürgen}}, isbn = {{978-3-939350-56-9 }}, title = {{{Vorausschau ind Technologieplanung. 4. Symposium für Vorausschau und Technologieplanung Heinz Nixdorf Institut, 30. und 31. Oktober 2008}}}, volume = {{Band 237}}, year = {{2008}}, } @inproceedings{41474, author = {{Seifert, Andreas and Schaper, Niclas}}, booktitle = {{Tagung „Kompetenzdiagnose und Kompetenzentwicklung in der Lehrerbildung“ des CEVET und PLAZ}}, location = {{Paderborn}}, title = {{{Erste Ergebnisse zur Messung pädagogischer Kompetenz in der universitären Lehrerausbildung.}}}, year = {{2008}}, } @inproceedings{41473, author = {{Seifert, Andreas and Schaper, Niclas and Hilligus, Annegret Helen and Grafe, Silke}}, booktitle = {{AEPF-Tagung „Kompetenz – Modellierung – Diagnostik – Entwicklung – Förderung“}}, location = {{Kiel}}, title = {{{Messung erziehungswissenschaftlicher Kompetenz in der Lehrerausbildung.}}}, year = {{2008}}, } @article{23483, abstract = {{The emitted radiation from semiconductor nanostructures due to the excitation with intense ultrashort optical laser pulses is analyzed. Semiconductor Bloch equations that consistently describe the coupled light-field-induced interband and intraband dynamics are solved numerically. It is demonstrated that the intraband dynamics considerably influences the light emission in the regime of extreme nonlinear optics. In particular, the intraband acceleration significantly modifies the dynamics of the interband polarization which results in a strong enhancement of high-harmonic generation.}}, author = {{Golde, D. and Meier, Torsten and Koch, S. W.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{7}}, title = {{{High harmonics generated in semiconductor nanostructures by the coupled dynamics of optical inter- and intraband excitations}}}, doi = {{10.1103/physrevb.77.075330}}, volume = {{77}}, year = {{2008}}, } @inproceedings{24981, author = {{Güdde, J. and Rohleder, M. and Meier, Torsten and Koch, S.W. and Höfer, U.}}, booktitle = {{Frontiers in Optics 2008/Laser Science XXIV/Plasmonics and Metamaterials/Optical Fabrication and Testing}}, isbn = {{978-1-55752-861-2}}, location = {{Rochester, New York United States}}, title = {{{Generation and Time-Resolved Detection of Coherently Controlled Electric Currents at Surfaces}}}, doi = {{10.1364/fio.2008.fmi3}}, year = {{2008}}, } @article{40411, author = {{Pasenow, B. and Duc, H.T. and Meier, Torsten and Koch, S.W.}}, issn = {{0038-1098}}, journal = {{Solid State Communications}}, keywords = {{Materials Chemistry, Condensed Matter Physics, General Chemistry}}, number = {{1-2}}, pages = {{61--65}}, publisher = {{Elsevier BV}}, title = {{{Rabi flopping of charge and spin currents generated by ultrafast two-colour photoexcitation of semiconductor quantum wells}}}, doi = {{10.1016/j.ssc.2007.09.029}}, volume = {{145}}, year = {{2008}}, } @inproceedings{2370, author = {{Woehrle, Matthias and Plessl, Christian and Lim, Roman and Beutel, Jan and Thiele, Lothar}}, booktitle = {{IEEE Int. Conf. on Sensor Networks, Ubiquitous, and Trustworthy Computing (SUTC)}}, isbn = {{978-0-7695-3158-8}}, keywords = {{WSN, testing, verification}}, pages = {{201--208}}, publisher = {{IEEE Computer Society}}, title = {{{EvAnT: Analysis and Checking of event traces for Wireless Sensor Networks}}}, doi = {{10.1109/SUTC.2008.24}}, year = {{2008}}, } @inproceedings{2364, author = {{Schumacher, Tobias and Meiche, Robert and Kaufmann, Paul and Lübbers, Enno and Plessl, Christian and Platzner, Marco}}, booktitle = {{Proc. Int. Conf. on Engineering of Reconfigurable Systems and Algorithms (ERSA)}}, isbn = {{1-60132-064-7}}, pages = {{245--251}}, publisher = {{CSREA Press}}, title = {{{A Hardware Accelerator for k-th Nearest Neighbor Thinning}}}, year = {{2008}}, } @inproceedings{2372, author = {{Schumacher, Tobias and Plessl, Christian and Platzner, Marco}}, booktitle = {{Many-core and Reconfigurable Supercomputing Conference (MRSC)}}, keywords = {{IMORC, IP core, interconnect}}, title = {{{IMORC: An infrastructure for performance monitoring and optimization of reconfigurable computers}}}, year = {{2008}}, } @article{58594, author = {{Ameerunisha Begum, M.S. and Seewald, Oliver and Flörke, Ulrich and Henkel, Gerald}}, issn = {{0020-1693}}, journal = {{Inorganica Chimica Acta}}, number = {{7}}, pages = {{1868--1874}}, publisher = {{Elsevier BV}}, title = {{{From the {Cu(μ2-S)N}4 butterfly architecture to the {Cu(μ3-S)N}12 double wheel}}}, doi = {{10.1016/j.ica.2007.09.047}}, volume = {{361}}, year = {{2008}}, }