TY - JOUR AU - Thierfelder, C. AU - Hermann, A. AU - Schwerdtfeger, P. AU - Schmidt, Wolf Gero ID - 13690 IS - 4 JF - Physical Review B SN - 1098-0121 TI - Strongly bonded water monomers on the ice Ih basal plane: Density-functional calculations VL - 74 ER - TY - JOUR AU - Biering, S. AU - Hermann, A. AU - Schmidt, Wolf Gero ID - 13691 IS - 23 JF - Physical Review B SN - 1098-0121 TI - Adsorption of water on chlorine-terminated Si(111) from first principles: Substrate-induced ordering versus intermolecular interactions VL - 73 ER - TY - JOUR AU - Seino, K. AU - Schmidt, Wolf Gero AU - Ohtake, A. ID - 13694 IS - 3 JF - Physical Review B SN - 1098-0121 TI - Ga-richGaAs(001)surface fromab initiocalculations: Atomic structure of the(4×6)and(6×6)reconstructions VL - 73 ER - TY - JOUR AU - Hahn, P. H. AU - Schmidt, Wolf Gero AU - Bechstedt, F. ID - 13695 IS - 24 JF - Physical Review B SN - 1098-0121 TI - Molecular electronic excitations calculated from a solid-state approach: Methodology and numerics VL - 72 ER - TY - JOUR AU - Ortmann, F. AU - Bechstedt, F. AU - Schmidt, Wolf Gero ID - 13845 IS - 20 JF - Physical Review B SN - 1098-0121 TI - Semiempirical van der Waals correction to the density functional description of solids and molecular structures VL - 73 ER - TY - JOUR AU - Höink, V. AU - Sacher, Marc AU - Schmalhorst, J. AU - Reiss, G. AU - Engel, D. AU - Weis, T. AU - Ehresmann, A. ID - 29685 IS - 22 JF - Physical Review B KW - Condensed Matter Physics KW - Electronic KW - Optical and Magnetic Materials SN - 1098-0121 TI - Thermal stability of magnetic nanostructures in ion-bombardment-modified exchange-bias systems VL - 73 ER - TY - JOUR AB - The coherent ultrafast optical injection and the temporal evolution of charge and spin currents in semiconductors is analyzed using a microscopic many-body theory. The approach is based on the semiconductor Bloch equations and includes light-field-induced intraband and interband excitations, excitonic effects, and carrier–LO-phonon and carrier-carrier scattering processes. The relaxation effects are treated both in the second Born-Markov approximation and on the level of quantum kinetic theory including memory effects. The dynamics of the charge and spin currents is evaluated numerically for a one-dimensional model system. The dependence of the currents and their decay on the temperature, the excitation intensities, and the frequencies of the incident light fields is discussed. Whereas the overall decay dynamics is described well within the Markov approximation, the quantum kinetic theory predicts additional oscillatory signatures in the current transients. AU - Duc, H. T. AU - Vu, Q. T. AU - Meier, Torsten AU - Haug, H. AU - Koch, S. W. ID - 23492 IS - 16 JF - Physical Review B SN - 1098-0121 TI - Temporal decay of coherently optically injected charge and spin currents due to carrier–LO-phonon and carrier-carrier scattering VL - 74 ER - TY - JOUR AU - Borri, P. AU - Langbein, W. AU - Woggon, U. AU - Stavarache, V. AU - Reuter, Dirk AU - Wieck, A. D. ID - 8681 JF - Physical Review B SN - 1098-0121 TI - Exciton dephasing via phonon interactions in InAs quantum dots: Dependence on quantum confinement ER - TY - JOUR AU - Pfalz, S. AU - Winkler, R. AU - Nowitzki, T. AU - Reuter, Dirk AU - Wieck, A. D. AU - Hägele, D. AU - Oestreich, M. ID - 8682 JF - Physical Review B SN - 1098-0121 TI - Optical orientation of electron spins in GaAs quantum wells ER - TY - JOUR AB - The interaction of electrons with LO phonons provides an important mechanism of optical dephasing and carrier scattering for the two-dimensional electron gas in semiconductor quantum wells. In this paper, the corresponding ultrafast nonlinearities for off-resonant and resonant intersubband excitations are investigated. Quantum kinetic effects of the electron-phonon interaction and the corresponding violation of the microscopic energy conservation yield a qualitative different picture compared to the standard Markovian theory, if the phonon energy is larger than the intersubband-gap energy. AU - Butscher, Stefan AU - Förstner, Jens AU - Waldmüller, Inès AU - Knorr, Andreas ID - 4249 IS - 4 JF - Physical Review B KW - tet_topic_qw SN - 1098-0121 TI - Ultrafast electron-phonon interaction of intersubband transitions: Quantum kinetics from adiabatic following to Rabi-oscillations VL - 72 ER - TY - JOUR AB - A microscopic description based on the density matrix formalism is developed to describe the dynamics of photoemission of hot electrons at semiconductor surfaces, including the interaction of bulk and surface states. The equations of motion for the electronic occupations and transitions include the interaction with arbitrary optical fields as well as the electron-phonon coupling. Model wave functions are used to qualitatively describe the bulk-surface dynamics and the subsequent time resolved two-photon photoemission s2PPEd spectra. Our results suggest that it is possible to extract energetic and temporal information of the underlying dynamical occupations of the intermediate states from the 2PPE spectra. AU - Zeiser, A. AU - Bücking, N. AU - Förstner, Jens AU - Knorr, A. ID - 4254 IS - 24 JF - Physical Review B SN - 1098-0121 TI - Microscopic theory of electron dynamics and time-resolved two-color two-photon photoemission at semiconductor surfaces VL - 71 ER - TY - JOUR AB - Using a fully quantized description of strongly confined electrons interacting with acoustic phonons and the photon field, the nonstationary resonance-fluorescence spectra of a semiconductor quantum dot are investigated. For excitation pulses with durations approaching typical electron-phonon scattering times, the virtual quantum processes yield an observable electron-phonon sideband broadening. AU - Ahn, K. J. AU - Förstner, Jens AU - Knorr, A. ID - 4260 IS - 15 JF - Physical Review B KW - tet_topic_qd SN - 1098-0121 TI - Resonance fluorescence of semiconductor quantum dots: Signatures of the electron-phonon interaction VL - 71 ER - TY - JOUR AU - Schumacher, Stefan AU - Czycholl, G. AU - Jahnke, F. AU - Kudyk, I. AU - Rückmann, H. I. AU - Gutowski, J. AU - Gust, A. AU - Alexe, G. AU - Hommel, D. ID - 15849 JF - Physical Review B SN - 1098-0121 TI - Polariton propagation in shallow-confinement heterostructures: Microscopic theory and experiment showing the breakdown of the dead-layer concept ER - TY - JOUR AU - Schumacher, Stefan AU - Czycholl, G. AU - Jahnke, F. AU - Kudyk, I. AU - Wischmeier, L. AU - Rückmann, I. AU - Voss, T. AU - Gutowski, J. AU - Gust, A. AU - Hommel, D. ID - 15850 JF - Physical Review B SN - 1098-0121 TI - Coherent propagation of polaritons in semiconductor heterostructures: Nonlinear pulse transmission in theory and experiment ER - TY - JOUR AU - Bechstedt, F. AU - Seino, K. AU - Hahn, P. H. AU - Schmidt, Wolf Gero ID - 13696 IS - 24 JF - Physical Review B SN - 1098-0121 TI - Quasiparticle bands and optical spectra of highly ionic crystals: AlN and NaCl VL - 72 ER - TY - JOUR AU - Fuchs, F. AU - Schmidt, Wolf Gero AU - Bechstedt, F. ID - 13702 IS - 7 JF - Physical Review B SN - 1098-0121 TI - Understanding the optical anisotropy of oxidized Si(001) surfaces VL - 72 ER - TY - JOUR AU - Leitsmann, R. AU - Schmidt, Wolf Gero AU - Hahn, P. H. AU - Bechstedt, F. ID - 13705 JF - Physical Review B SN - 1098-0121 TI - Second-harmonic polarizability including electron-hole attraction from band-structure theory VL - 71 ER - TY - JOUR AU - Hermann, A. AU - Schmidt, Wolf Gero AU - Bechstedt, F. ID - 13706 JF - Physical Review B SN - 1098-0121 TI - Optical response ofπ-conjugated molecular monolayer adsorbed on the semiconductor Si(001) surface: A first-principles study VL - 71 ER - TY - JOUR AU - Hahn, P. H. AU - Schmidt, Wolf Gero AU - Bechstedt, F. ID - 13846 IS - 24 JF - Physical Review B SN - 1098-0121 TI - Molecular electronic excitations calculated from a solid-state approach: Methodology and numerics VL - 72 ER - TY - JOUR AB - Significant aspects of the light–matter interaction can be strongly modified in suitably designed systems consisting of semiconductor nanostructures and dielectric photonic crystals. To analyze such effects, a microscopic theory is presented, which is capable of describing the optoelectronic properties of such hybrid systems via a self-consistent solution of the dynamics of the optical field and the photoexcitations of the material. The theory is applied to investigate the local excitonic resonances, which arise as a consequence of the modified Coulomb interaction in the vicinity of a structured dielectric medium. The excitation of a coherent superposition of the spatially inhomogeneous optical transitions induces an intricate wave packet dynamics. In the presence of dephasing and relaxation processes, the coherent oscillations are damped and the photoexcited carriers relax into spatially inhomogeneous quasi-equilibrium distributions. AU - Pasenow, B. AU - Reichelt, Matthias AU - Stroucken, T. AU - Meier, Torsten AU - Koch, S. W. ID - 23502 IS - 19 JF - Physical Review B SN - 1098-0121 TI - Excitonic wave packet dynamics in semiconductor photonic-crystal structures VL - 71 ER - TY - JOUR AU - Oszwałdowski, R. AU - Reichelt, Matthias AU - Meier, Torsten AU - Koch, S. W. AU - Rohlfing, Michael ID - 23503 IS - 23 JF - Physical Review B SN - 1098-0121 TI - Nonlinear optical response of the Si ( 111 ) − ( 2 × 1 ) surface exciton: Influence of biexciton many-body correlations VL - 71 ER - TY - JOUR AB - A set of (Ga0.77In0.23)As/Ga(NxAs1−x) heterostructures is studied by time-resolved photoluminescence. Four samples with nitrogen concentrations from x=0.48% up to x=2.2% are investigated at different temperatures and with different excitation densities. The experiments suggest that the heterostructure band offset is type I for x=0.48% and type II for x=2.2%. The situation is more complex for x=0.72% and x=1.25%, since these samples are close to the transition from type I to type II. The experimental findings are analyzed using a detailed microscopic theory. Numerical calculations describe the measured data well. In particular, the interpretation of the experimental results concerning the band alignment is confirmed by the theoretical analysis. AU - Hantke, K. AU - Heber, J. D. AU - Schlichenmaier, C. AU - Thränhardt, A. AU - Meier, Torsten AU - Kunert, B. AU - Volz, K. AU - Stolz, W. AU - Koch, S. W. AU - Rühle, W. W. ID - 23501 IS - 16 JF - Physical Review B SN - 1098-0121 TI - Time-resolved photoluminescence of type-I and type-II (GaIn) As/Ga (NAs) heterostructures VL - 71 ER - TY - JOUR AB - The optical and electronic properties of semiconductor heterostructures in the vicinity of photonic crystals are discussed. The theoretical approach provides a self-consistent solution of the dynamics of the electromagnetic field and the material excitations. Due to the influence of the structured dielectric environment on the Coulomb interaction, the exciton resonances and the quasiequilibrium carrier densities in the spatially homogeneous semiconductor become space dependent. It is demonstrated that these inhomogeneities lead to distinct modifications of the optical absorption and gain spectra. As an application, numerically calculated density-dependent optical spectra are analyzed for an array of semiconductor quantum wires which are close to a two-dimensional photonic crystal. The spatial inhomogeneities result in novel excitonic absorption features and modification of the optical gain in these structures. AU - Reichelt, Matthias AU - Pasenow, B. AU - Meier, Torsten AU - Stroucken, T. AU - Koch, S. W. ID - 23496 IS - 3 JF - Physical Review B SN - 1098-0121 TI - Spatially inhomogeneous optical gain in semiconductor photonic-crystal structures VL - 71 ER - TY - JOUR AU - Christ, A. AU - Zentgraf, Thomas AU - Kuhl, J. AU - Tikhodeev, S. G. AU - Gippius, N. A. AU - Giessen, H. ID - 1746 IS - 12 JF - Physical Review B SN - 1098-0121 TI - Optical properties of planar metallic photonic crystal structures: Experiment and theory VL - 70 ER - TY - JOUR AU - Langbein, W. AU - Borri, P. AU - Woggon, U. AU - Stavarache, V. AU - Reuter, Dirk AU - Wieck, A. D. ID - 8704 JF - Physical Review B SN - 1098-0121 TI - Control of fine-structure splitting and biexciton binding inInxGa1−xAsquantum dots by annealing ER - TY - JOUR AU - Langbein, W. AU - Borri, P. AU - Woggon, U. AU - Stavarache, V. AU - Reuter, Dirk AU - Wieck, A. ID - 8709 JF - Physical Review B SN - 1098-0121 TI - Radiatively limited dephasing in InAs quantum dots ER - TY - JOUR AU - Deviatov, E. V. AU - Würtz, A. AU - Lorke, A. AU - Yu. Melnikov, M. AU - Dolgopolov, V. T. AU - Reuter, Dirk AU - Wieck, A. D. ID - 8710 JF - Physical Review B SN - 1098-0121 TI - Two relaxation mechanisms observed in transport between spin-split edge states at high imbalance ER - TY - JOUR AB - The adiabatic driving of the resonant electron dynamics in a one-dimensional resonant photonic band gap is proposed as an optical mechanism for nonlinear ultrafast switching. Pulsed excitation inside the photonic gap results in an ultrafast suppression and recovery of the gap. This behavior results from the adiabatic carrier dynamics due to rapid radiative damping inside the band gap. AU - Schaarschmidt, Martin AU - Förstner, Jens AU - Knorr, Andreas AU - Prineas, John P. AU - Nielsen, Nils C. AU - Kuhl, Jürgen AU - Khitrova, Galina AU - Gibbs, Hyatt M. AU - Giessen, Harald AU - Koch, Stephan W. ID - 4270 IS - 23 JF - Physical Review B KW - tet_topic_qw SN - 1098-0121 TI - Adiabatically driven electron dynamics in a resonant photonic band gap: Optical switching of a Bragg periodic semiconductor VL - 70 ER - TY - JOUR AB - We investigate the temporal and spectral properties of subpicosecond pulses transmitted on the heavy-hole exciton transition through a multiple-quantum-well Bragg structure, exhibiting a one-dimensional photonic band gap. At low light intensities, a temporal propagation beating is observed. This beating is strongly dependent on the optical dephasing time T2 which is dominated by the radiative interwell coupling. In an intermediate intensity regime, the Pauli-blocking nonlinearity leads to gradual suppression of the photonic band gap and vanishing of the linear propagation beating. For highly nonlinear excitation, we find signatures of selfinduced transmission due to Rabi flopping and adiabatic following of the carrier density. Numerical simulations using the semiconductor Maxwell-Bloch equations are in excellent agreement with the experimental data up to intensities for which higher many-particle correlations become more important and self-phase modulation occurs in the sample substrate. AU - Nielsen, N. C. AU - Kuhl, J. AU - Schaarschmidt, M. AU - Förstner, Jens AU - Knorr, A. AU - Koch, S. W. AU - Khitrova, G. AU - Gibbs, H. M. AU - Giessen, H. ID - 4277 IS - 7 JF - Physical Review B KW - tet_topic_qw SN - 1098-0121 TI - Linear and nonlinear pulse propagation in a multiple-quantum-well photonic crystal VL - 70 ER - TY - JOUR AU - Waldmüller, I. AU - Förstner, Jens AU - Lee, S.-C. AU - Knorr, A. AU - Woerner, M. AU - Reimann, K. AU - Kaindl, R. A. AU - Elsaesser, T. AU - Hey, R. AU - Ploog, K. H. ID - 673 IS - 20 JF - Physical Review B SN - 1098-0121 TI - Optical dephasing of coherent intersubband transitions in a quasi-two-dimensional electron gas VL - 69 ER - TY - JOUR AU - Seino, K. AU - Schmidt, Wolf Gero AU - Bechstedt, F. ID - 13719 JF - Physical Review B SN - 1098-0121 TI - Organic modification of surface electronic properties: A first-principles study of uracil on Si(001) VL - 69 ER - TY - JOUR AU - Schmalhorst, J. AU - Sacher, Marc AU - Höink, V. AU - Reiss, G. AU - Engel, D. AU - Ehresmann, A. ID - 29693 IS - 18 JF - Physical Review B KW - Condensed Matter Physics KW - Electronic KW - Optical and Magnetic Materials SN - 1098-0121 TI - X-ray absorption and magnetic circular dichroism studies of ion-bombarded ferromagnet-antiferromagnet bilayers VL - 70 ER - TY - JOUR AU - Schmalhorst, J. AU - Kämmerer, S. AU - Sacher, Marc AU - Reiss, G. AU - Hütten, A. AU - Scholl, A. ID - 29695 IS - 2 JF - Physical Review B KW - Condensed Matter Physics KW - Electronic KW - Optical and Magnetic Materials SN - 1098-0121 TI - Interface structure and magnetism of magnetic tunnel junctions with aCo2MnSielectrode VL - 70 ER -