@inproceedings{44068, abstract = {{The band structure and wave functions of GaAs quantum wells are computed via k.p band structure theory including anisotropy and spin splitting. Using these results, the process of generating photocurrents by optical excitation is analyzed. Depending on the symmetry of the material, the direction of the laser beam, and the polarization direction of the light field/s, one can coherently generate charge and/or spin photocurrents on ultrashort time scales. The direction, the strength, and the dynamics of these photocurrents are computed and discussed.}}, author = {{Meier, Torsten and Duc, Huynh Thanh and Foerstner, Jens}}, booktitle = {{DPG Spring meeting 2009}}, issn = {{0420-0195}}, location = {{Dresden, Germany}}, number = {{5}}, title = {{{Photo-and spin current generation and dynamics in semiconductor nanostructures}}}, volume = {{44}}, 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{44112, abstract = {{Homogeneous and inhomogeneous broadening of heavy- and light-hole excitons in semiconductor quantum wells are measured along with the excitation dependence of both broadenings. Isolation of disorder-induced broadening is possible with spectra in different coherent pathways.}}, author = {{Meier, Torsten and Zhang, Tianhao and Bristow, Alan D. and Dai, Xingcan and Kuznetsova, Irina and Thomas, P. and Cundiff, S.T.}}, booktitle = {{Quantum Electronics and Laser Science Conference}}, isbn = {{978-1-55752-859-9}}, location = {{San Jose, California United States}}, publisher = {{Optical Society of America}}, title = {{{Direct determination of exciton homogeneous and inhomogeneous linewidths in semiconductor quantum wells with two-dimensional fourier transform spectroscopy}}}, year = {{2008}}, } @inproceedings{44110, author = {{Meier, Torsten and Duc, Huynh Thanh and Koch, S.W. and Pasenow, B.}}, booktitle = {{72nd annual meeting and DPG spring meeting of the Condensed Matter Section and the Divisions}}, location = {{Berlin, Germany}}, title = {{{Intensity dependence of charge and spin currents generated by ultrafast two-color photoexcitation of semiconductor quantum wells}}}, volume = {{43}}, year = {{2008}}, } @inproceedings{44111, author = {{Meier, Torsten and Koch, S.W. and Pasenow, B.}}, booktitle = {{72nd annual meeting and DPG spring meeting of the Condensed Matter Section and the Divisions}}, location = {{Berlin, Germany}}, title = {{{Influence of heavy-hole light-hole band mixing on the strength of optically generated spin-currents in III-V semiconductor quantum wells}}}, volume = {{42}}, 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}}, } @inbook{44109, author = {{Meier, Torsten and Pasenow, B. and Reichelt, Matthias and Stroucken, T.}}, booktitle = {{Nanophotonic Materials: Photonic Crystals, Plasmonics, and Metamaterials}}, editor = {{Busch, Kurt and Kitzerow, H.-S. and Wehrspohn, Ralf B.}}, isbn = {{9783527408580 }}, pages = {{15--38}}, publisher = {{Wiley‐VCH Verlag GmbH & Co. KGaA}}, title = {{{Microscopic Analysis of the Optical and Electronic Properties of Semiconductor Photonic-Crystal Structures}}}, doi = {{10.1002/9783527621880.ch2}}, 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}}, } @inbook{23485, abstract = {{The ultrafast dynamics of optical excitations in semiconductors and semiconductor nanostructures can be computed on a microscopic theoretical basis using the semiconductor Bloch equations. This set of equations allows one to nonperturbatively evaluate light-field-induced intraband and interband excitations and is also well suited for the analysis of many-body effects such as excitonic resonances and carrier-carrier and carrier-phonon scattering processes. In this article we start with a description of an experimental observation of coherent spin photocurrents, then we briefly introduce the theoretical approach and review some results of our theory concerning the microscopic description of the ultrafast coherent optical generation and the temporal decay of charge and spin currents in semiconductor nanostructures. The computed transients show an enhanced damping of the spin current relative to the charge current as a consequence of Coulomb scattering between carriers with opposite spin. The influence of quantum kinetic memory effects on the dynamics of the photocurrents is analyzed by evaluating the scattering terms beyond the Markov approximation.}}, author = {{Meier, Torsten and Duc, Huynh Thanh and Vu, Quang Tuyen and Pasenow, Bernhard and Hübner, Jens and Chatteryee, Sangam and Rühle, Wolfgang W. and Haug, Hartmut and Koch, Stephan W.}}, booktitle = {{Advances in Solid State Physics}}, isbn = {{978-3-540-38234-8}}, pages = {{199--210}}, publisher = {{Springer}}, title = {{{Ultrafast Dynamics of Optically-Induced Charge and Spin Currents in Semiconductors}}}, doi = {{10.1007/978-3-540-38235-5_15}}, year = {{2008}}, } @inbook{24979, abstract = {{The ultrafast dynamics of optical excitations in semiconductors and semiconductor nanostructures can be computed on a microscopic theoretical basis using the semiconductor Bloch equations. This set of equations allows one to nonperturbatively evaluate light-field-induced intraband and interband excitations and is also well suited for the analysis of many-body effects such as excitonic resonances and carrier-carrier and carrier-phonon scattering processes. In this article we start with a description of an experimental observation of coherent spin photocurrents, then we briefly introduce the theoretical approach and review some results of our theory concerning the microscopic description of the ultrafast coherent optical generation and the temporal decay of charge and spin currents in semiconductor nanostructures. The computed transients show an enhanced damping of the spin current relative to the charge current as a consequence of Coulomb scattering between carriers with opposite spin. The influence of quantum kinetic memory effects on the dynamics of the photocurrents is analyzed by evaluating the scattering terms beyond the Markov approximation.}}, author = {{Meier, Torsten and Duc, Huynh Thanh and Vu, Quang Tuyen and Pasenow, Bernhard and Hübner, Jens and Chatteryee, Sangam and Rühle, Wolfgang W. and Haug, Hartmut and Koch, Stephan W.}}, booktitle = {{Advances in Solid State Physics}}, isbn = {{978-3-540-38234-8}}, pages = {{199--210}}, publisher = {{Springer}}, title = {{{Ultrafast Dynamics of Optically-Induced Charge and Spin Currents in Semiconductors}}}, doi = {{10.1007/978-3-540-38235-5_15}}, 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}}, } @article{24976, author = {{Pasenow, B. and Duc, H.T. and Meier, Torsten and Koch, S.W.}}, issn = {{0038-1098}}, journal = {{Solid State Communications}}, pages = {{61--65}}, 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}}, } @article{23482, author = {{Pasenow, B. and Duc, H.T. and Meier, Torsten and Koch, S.W.}}, issn = {{0038-1098}}, journal = {{Solid State Communications}}, pages = {{61--65}}, 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}}, year = {{2008}}, } @article{23484, author = {{Golde, D. and Meier, T. 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{43266, abstract = {{In extreme nonlinear optics the Rabi frequency is comparable to or even larger than the transition frequency. Numerical solutions of the semiconductor Bloch equations show that the response of semiconductor quantum wells and wires differs characteristically from that of a two-level system in this highly nonperturbative regime. The main reason for these differences is the continuous electronic dispersion, and, to a lesser degree, the Coulombic interaction effects.}}, author = {{Golde, D. and Meier, Torsten and Koch, S.W.}}, booktitle = {{Ultrafast Phenomena XV: Proceedings of the 15th International Conference}}, location = {{Pacific Grove, USA}}, pages = {{689–691}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Modeling of the Extreme Nonlinear Optical Response of Semiconductor Nanostructures}}}, doi = {{10.1007/978-3-540-68781-8_221}}, volume = {{88}}, year = {{2007}}, } @article{43268, abstract = {{The combination of dielectric photonic crystals and semiconductor nanostructures makes it possible to design many important aspects of the optoelectronic system response. A spatially-varying dielectric environment induces modifications of the transversal and the longitudinal components of the electromagnetic field which have to be included in the self-consistent microscopic analysis of the optical properties of hybrid semiconductor photonic-crystal structures. In this paper, the development of a semiclassical microscopic theory is reviewed. Whereas the classical electromagnetic field is described at the level of Maxwell's equations, a full many-body quantum theory is used for the interacting electronic excitations in the semiconductor material. Relevant examples of the numerical solutions of the resulting Maxwell semiconductor Bloch equations are presented showing, e.g., characteristic modifications of excitonic absorption spectra, the spatio-temporal dynamics of electronic wave packets, as well as an increase of the optical gain in properly designed device geometries.}}, author = {{Pasenow, B. and Reichelt, Matthias and Stroucken, T. and Meier, Torsten and Koch, S.W.}}, journal = {{physica status solidi (a)}}, number = {{11}}, pages = {{3600--3617}}, publisher = {{WILEY‐VCH Verlag}}, title = {{{Microscopic analysis of the optical and electronic properties of semiconductor photonic‐crystal structures}}}, doi = {{10.1002/pssa.200776403}}, volume = {{204}}, year = {{2007}}, } @article{43267, abstract = {{The imaginary part of two-dimensional Fourier-transform spectra in the rephasing and nonrephasing modes is used to analyze the homogeneous and inhomogeneous broadening of excitonic resonances in semiconductor nanostructures. Microscopic calculations that include heavy- and light-hole excitons as well as coherent biexcitonic many-body correlations reveal distinct differences between the rephasing and nonrephasing spectra. A procedure is proposed that allows separation of disorder-induced broadening in complex systems that show several coupled resonances.}}, author = {{Kuznetsova, I. and Meier, Torsten and Cundiff, S.T. and Thomas, P. }}, journal = {{Physical Review B}}, number = {{15}}, publisher = {{American Physical Society}}, title = {{{Determination of homogeneous and inhomogeneous broadening in semiconductor nanostructures by two-dimensional Fourier-transform optical spectroscopy}}}, doi = {{10.1103/PhysRevB.76.153301}}, volume = {{76}}, year = {{2007}}, } @inproceedings{43263, abstract = {{Employing the quantum interference among one- and two-photon excitations induced by ultrashort two-color laser pulses it is possible to generate charge and spin currents in semiconductors and semiconductor nanostructures on femtosecond time scales. Here, it is reviewed how the excitation process and the dynamics of such photocurrents can be described on the basis of a microscopic many-body theory. Numerical solutions of the semiconductor Bloch equations (SBE) provide a detailed description of the time-dependent material excitations. Applied to the case of photocurrents, numerical solutions of the SBE for a two-band model including many-body correlations on the second-Born Markov level predict an enhanced damping of the spin current relative to that of the charge current. Interesting effects are obtained when the scattering processes are computed beyond the Markovian limit. Whereas the overall decay of the currents is basically correctly described already within the Markov approximation, quantum-kinetic calculations show that memory effects may lead to additional oscillatory signatures in the current transients. When transitions to coupled heavy- and light-hole valence bands are incorporated into the SBE, additional charge and spin currents, which are not described by the two-band model, appear.}}, author = {{Meier, Torsten and Pasenow, B. and Duc, H.T. and Vu, Q.T. and Haug, H. and Koch, S.W.}}, booktitle = {{Ultrafast Phenomena in Semiconductors and Nanostructure Materials XI and Semiconductor Photodetectors IV}}, publisher = {{SPIE}}, title = {{{Ultrafast dynamics of photoexcited charge and spin currents in semiconductor nanostructures}}}, doi = {{10.1117/12.696338}}, volume = {{6471}}, year = {{2007}}, } @inproceedings{44117, abstract = {{Two-Dimensional Fourier-Transform-Spectroscopy (2DFTS) is a novel method for the experimental investigation of many-body interactions in semiconductor nanostructures [1]. It displays directly the heavy-hole (hh) and light-hole (lh) excitonic transitions in III-V-quantum wells along the main diagonal of a two-dimensional plot which is spanned by the excitation energy −ħωτ and the emission energy ħωτ. In addition, characteristic signatures due to continuum excitations appear as well as mixed peaks in off-diagonal positions resulting from various couplings. Using a one-dimensional tight-binding model which contains the correct selection rules we compute 2DFTS in the coherent χ(3)-limit. By comparing theoretical spectra resulting from different orders in the Coulomb interaction we can clearly identify the influence of the many-particle interaction on the various signatures that are visible in the spectrograms. The distribution of the peak heights, their magnitude, and their lineshape are of particular interest. Co-circularly polarized excitation pulses are considered.}}, author = {{Meier, Torsten and Kuznetsova, Irina and Thomas, Peter and Zhang, Tianhao and Cundiff, Steven T.}}, booktitle = {{International Quantum Electronics Conference}}, isbn = {{1-4244-931-4}}, location = {{Munich, Germany}}, title = {{{Investigation of Coulomb-induced coupling in semiconductor nanostructures using 2D Fourier-Transform-Spectroscopy}}}, year = {{2007}}, } @inproceedings{44118, abstract = {{Many-body correlations of excitons in semiconductors are explored experimentally with two-dimensional Fourier transform spectroscopy and modeled by a microscopic coherent χ(3) theory beyond the Hartree-Fock approximation with qualitative agreements under different excitation conditions.}}, author = {{Meier, Torsten and Zhang, Tianhao and Li, Xiaoqin and Cundiff, S.T. and Mirin, R. P. and Kuznetsova, Irina and Thomas, P.}}, booktitle = {{Quantum Electronics and Laser Science Conference}}, isbn = {{1557528349}}, location = {{Baltimore, Maryland United States}}, publisher = {{Optical Society of America}}, title = {{{Experimental and theoretical studies of exciton correlations using optical two-dimensional fourier transform spectroscopy}}}, year = {{2007}}, }