PC2 - User Project Publications (Universität Paderborn)

Simulation of Second Harmonic Generation from Photonic Nanostructures Using the Discontinuous Galerkin Time Domain Method

Y. Grynko, J. Förstner, in: Recent Trends in Computational Photonics, Springer International Publishing, 2017, pp. 261-284

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We apply the Discontinuous Galerkin Time Domain (DGTD) method for numerical simulations of the second harmonic generation from various metallic nanostructures. A Maxwell–Vlasov hydrodynamic model is used to describe the nonlinear effects in the motion of the excited free electrons in a metal. The results are compared with the corresponding experimental measurements for split-ring resonators and plasmonic gap antennas.

A Framework for the Synthesis of Approximate Circuits

L.M. Witschen, Master's thesis, Universität Paderborn, 2017

New design equations for turbulent forced convection heat transfer and pressure loss in pillow-plate channels

M. Piper, A. Zibart, E. Kenig, International Journal of Thermal Sciences (2017), pp. 459-468

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Numerical Investigation of Liquid Falling Film Flow on the Wavy Surface of Vertical Pillow Plates

A. Zibart, E. Kenig. Numerical Investigation of Liquid Falling Film Flow on the Wavy Surface of Vertical Pillow Plates. In: 12th SDEWES Conference, Dubrovnik, Croatia, 2017.

Efficient Branch and Bound on FPGAs Using Work Stealing and Instance-Specific Designs

H. Riebler, M. Lass, R. Mittendorf, T. Löcke, C. Plessl, ACM Transactions on Reconfigurable Technology and Systems (TRETS) (2017), 10(3), pp. 24:1-24:23

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Branch and bound (B&B) algorithms structure the search space as a tree and eliminate infeasible solutions early by pruning subtrees that cannot lead to a valid or optimal solution. Custom hardware designs significantly accelerate the execution of these algorithms. In this article, we demonstrate a high-performance B&B implementation on FPGAs. First, we identify general elements of B&B algorithms and describe their implementation as a finite state machine. Then, we introduce workers that autonomously cooperate using work stealing to allow parallel execution and full utilization of the target FPGA. Finally, we explore advantages of instance-specific designs that target a specific problem instance to improve performance. We evaluate our concepts by applying them to a branch and bound problem, the reconstruction of corrupted AES keys obtained from cold-boot attacks. The evaluation shows that our work stealing approach is scalable with the available resources and provides speedups proportional to the number of workers. Instance-specific designs allow us to achieve an overall speedup of 47 × compared to the fastest implementation of AES key reconstruction so far. Finally, we demonstrate how instance-specific designs can be generated just-in-time such that the provided speedups outweigh the additional time required for design synthesis.

Using Approximate Computing in Scientific Codes

M. Lass, T. Kühne, C. Plessl, in: Workshop on Approximate Computing (AC), 2016

Light scattering by ice crystals of cirrus clouds: From exact numerical methods to physical-optics approximation

A. Konoshonkin, A. Borovoi, N. Kustova, H. Okamoto, H. Ishimoto, Y. Grynko, J. Förstner, Journal of Quantitative Spectroscopy and Radiative Transfer (2016), 195, pp. 132-140

Abstract

DOI

The problem of light scattering by ice crystals of cirrus clouds is considered in the case of a hexagonal ice plate with different distributions over crystal orientations. The physical-optics approximation based on (E, M)-diffraction theory is compared with two exact numerical methods: the finite difference time domain (FDTD) and the discontinuous Galerkin time domain (DGTD) in order to estimate its accuracy and limits of applicability. It is shown that the accuracy of the physical-optics approximation is estimated as 95% for the averaged backscattering Mueller matrix for particles with size parameter more than 120. Furthermore, the simple expression that allows one to estimate the minimal number of particle orientations required for appropriate spatial averaging has been derived.

Light scattering by irregular particles much larger than the wavelength with wavelength-scale surface roughness

Y. Grynko, Y. Shkuratov, J. Förstner, Optics Letters (2016), 41(15), pp. 3491-3493

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We simulate light scattering by random irregular particles that have dimensions much larger than the wavelength of incident light at the size parameter of 𝑋=200 using the discontinuous Galerkin time domain method. A comparison of the DGTD solution for smoothly faceted particles with that obtained with a geometric optics model shows good agreement for the scattering angle curves of intensity and polarization. If a wavelength-scale surface roughness is introduced, diffuse scattering at rough interface results in smooth and featureless curves for all scattering matrix elements which is consistent with the laboratory measurements of real samples.

Light scattering by ice crystals of cirrus clouds: comparison of the physical optics methods

A.V. Konoshonkin, N.V. Kustova, A.G. Borovoi, Y. Grynko, J. Förstner, Journal of Quantitative Spectroscopy and Radiative Transfer (2016), 182, pp. 12-23

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The physical optics approximations are derived from the Maxwell equations. The scattered field equations by Kirchhoff, Stratton-Chu, Kottler and Franz are compared and discussed. It is shown that in the case of faceted particles, these equations reduce to a sum of the diffraction integrals, where every diffraction integral is associated with one plane–parallel optical beam leaving a particle facet. In the far zone, these diffraction integrals correspond to the Fraunhofer diffraction patterns. The paper discusses the E-, M- and (E, M)-diffraction theories as applied to ice crystals of cirrus clouds. The comparison to the exact solution obtained by the discontinuous Galerkin time domain method shows that the Kirchhoff diffraction theory is preferable.

The role of electromagnetic interactions in second harmonic generation from plasmonic metamaterials

J. Alberti, H. Linnenbank, S. Linden, Y. Grynko, J. Förstner, Applied Physics B (2016), 122(2), pp. 45-50

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We report on second harmonic generation spectroscopy on a series of rectangular arrays of split-ring resonators. Within the sample series, the lattice constants are varied, but the area of the unit cell is kept ﬁxed. The SHG signal intensity of the different arrays upon resonant excitation of the fundamental plasmonic mode strongly depends on the respective arrangement of the split-ring resonators. This ﬁnding can be explained by variations of the electromagnetic interactions between the split-ring resonators in the different arrays. The experimental results are in agreement with numerical calculations based on the discontinuous Galerkin time-domain method. (PDF) The role of electromagnetic interactions.... Available from: https://www.researchgate.net/publication/297612326_The_role_of_electromagnetic_interactions_in_second_harmonic_generation_from_plasmonic_metamaterials [accessed Aug 13 2018].

Eine neue Rippengeometrie zur Verbesserung des Wärmeübergangs in flüssigkeitsdurchströmten Kanälen

A. Zibart, R. Cherkezova, H.. Figge, E. Kenig. Eine neue Rippengeometrie zur Verbesserung des Wärmeübergangs in flüssigkeitsdurchströmten Kanälen. In: Jahrestreffen der ProcessNet-Fachgruppe Wärme- und Stoffübertragung,, Kassel, 2016.

Ultrasonic transmission measurements in the characterization of viscoelasticity utilizing polymeric waveguides

F. Bause, J. Rautenberg, N. Feldmann, M. Webersen, L. Claes, H. Gravenkamp, B. Henning, Measurement Science and Technology (2016), 27(10)

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Determination of the material properties of polymers using laser-generated broadband ultrasound

L. Claes, T. Meyer, F. Bause, J. Rautenberg, B. Henning, Journal of Sensors and Sensor Systems (2016), 5(1), pp. 187-196

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https://www.j-sens-sens-syst.net/5/187/2016/jsss-5-187-2016.pdf

Characterization of Continuous-fiber Reinforced Thermoplastics Using Thermoacoustically Excited Ultrasonic Lamb Waves

M. Webersen, S. Johannesmann, L. Claes, B. Henning, in: 2016 IEEE IUS~Proceedings, 2016

Intradomain Allosteric Network Modulates Calcium Affinity of the C-Type Lectin Receptor Langerin

J. Hanske, S. Aleksić, M. Ballaschk, M. Jurk, E. Shanina, M. Beerbaum, P. Schmieder, B.G. Keller, C. Rademacher, Journal of the American Chemical Society (2016), pp. 12176-12186

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Experimental realization of a polariton beam amplifier

D. Niemietz, J. Schmutzler, P. Lewandowski, K. Winkler, M. Aßmann, S. Schumacher, S. Brodbeck, M. Kamp, C. Schneider, S. Höfling, M. Bayer, Physical Review B (2016)

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Dynamics of exciton-polaritons in discrete lattices under incoherent localized pumping

A.V. Yulin, I.Y. Chestnov, X. Ma, S. Schumacher, U. Peschel, O.A. Egorov, Physical Review B (2016)

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Polarization dependence of nonlinear wave mixing of spinor polaritons in semiconductor microcavities

P. Lewandowski, O. Lafont, E. Baudin, C.K.P. Chan, P.T. Leung, S.M.H. Luk, E. Galopin, A. Lemaître, J. Bloch, J. Tignon, P. Roussignol, N.H. Kwong, R. Binder, S. Schumacher, Physical Review B (2016)

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Patterns and switching dynamics in polaritonic quantum fluids in semiconductor microcavities [Invited]

N.H. Kwong, C.Y. Tsang, M.H. Luk, Y.C. Tse, P. Lewandowski, C.K.P. Chan, P.T. Leung, S. Schumacher, R. Binder, Journal of the Optical Society of America B (2016), C153

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Experimental and Theoretical High-Energy-Resolution X-ray Absorption Spectroscopy: Implications for the Investigation of the Entatic State

N.J. Vollmers, P. Müller, A. Hoffmann, S. Herres-Pawlis, M. Rohrmüller, W.G. Schmidt, U. Gerstmann, M. Bauer, Inorganic Chemistry (2016), pp. 11694-11706

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Using Deep Convolutional Neural Networks in Monte Carlo Tree Search

T. Graf, M. Platzner, in: Computer and Games, 2016

Monte-Carlo Simulation Balancing Revisited

T. Graf, M. Platzner, in: IEEE Computational Intelligence and Games, 2016

Improved parameterization of the quantum harmonic oscillator model based on localized wannier functions to describe Van der Waals interactions in density functional theory

P. Partovi-Azar, M. Berg, S. Sanna, T.D. Kühne, International Journal of Quantum Chemistry (2016), 116(15), pp. 1160-1165

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Recently, the quantum harmonic oscillator model has been combined with maximally localized Wannier functions to account for long-range dispersion interactions in density functional theory calculations (Silvestrelli, J. Chem. Phys. 2013, 139, 054106). Here, we present a new, improved set of values for the three parameters involved in this scheme. To test the new parameter set we have computed the potential energy curves for various systems, including an isolated Ar2 dimer, two N2 dimers interacting within different configurations, and a water molecule physisorbed on pristine graphene. While the original set of parameters generally overestimates the interaction energies and underestimates the equilibrium distances, the new parameterization substantially improves the agreement with experimental and theoretical reference values. © 2016 Wiley Periodicals, Inc.

Assessing the accuracy of improved force-matched water models derived from Ab initio molecular dynamics simulations

A. Köster, T. Spura, G. Rutkai, J. Kessler, H. Wiebeler, J. Vrabec, T.D. Kühne, Journal of Computational Chemistry (2016), 37(19), pp. 1828-1838

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The accuracy of water models derived from ab initio molecular dynamics simulations by means on an improved force-matching scheme is assessed for various thermodynamic, transport, and structural properties. It is found that although the resulting force-matched water models are typically less accurate than fully empirical force fields in predicting thermodynamic properties, they are nevertheless much more accurate than generally appreciated in reproducing the structure of liquid water and in fact superseding most of the commonly used empirical water models. This development demonstrates the feasibility to routinely parametrize computationally efficient yet predictive potential energy functions based on accurate ab initio molecular dynamics simulations for a large variety of different systems. © 2016 Wiley Periodicals, Inc.

Solving the Pre-Marshalling Problem to Optimality with A* and IDA*

K. Tierney, D. Pacino, S. Voß, Flexible Services and Manufacturing Journal (2016), pp. 223-259

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Vibration eigenmodes of the Au-(5×2)/Si(111) surface studied by Raman spectroscopy and first-principles calculations

M. Liebhaber, B. Halbig, U. Bass, J. Geurts, S. Neufeld, S. Sanna, W.G. Schmidt, E. Speiser, J. Räthel, S. Chandola, N. Esser, Physical Review B (2016), 94(23)

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LiNbO3 electronic structure: Many-body interactions, spin-orbit coupling, and thermal effects

A. Riefer, M. Friedrich, S. Sanna, U. Gerstmann, A. Schindlmayr, W.G. Schmidt, Physical Review B (2016), 93(7), 075205

Abstract

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The influence of electronic many-body interactions, spin-orbit coupling, and thermal lattice vibrations on the electronic structure of lithium niobate is calculated from first principles. Self-energy calculations in the GW approximation show that the inclusion of self-consistency in the Green function G and the screened Coulomb potential W opens the band gap far stronger than found in previous G0W0 calculations but slightly overestimates its actual value due to the neglect of excitonic effects in W. A realistic frozen-lattice band gap of about 5.9 eV is obtained by combining hybrid density functional theory with the QSGW0 scheme. The renormalization of the band gap due to electron-phonon coupling, derived here using molecular dynamics as well as density functional perturbation theory, reduces this value by about 0.5 eV at room temperature. Spin-orbit coupling does not noticeably modify the fundamental gap but gives rise to a Rashba-like spin texture in the conduction band.

PhysRevB.93.075205.pdf - © 2016 American Physical…

LiTaO3 phonon dispersion and ferroelectric transition calculated from first principles

M. Friedrich, A. Schindlmayr, W.G. Schmidt, S. Sanna, Physica Status Solidi B (2016), 253(4), pp. 683-689

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The phonon dispersions of the ferro‐ and paraelectric phase of LiTaO3 are calculated within density‐functional perturbation theory. The longitudinal optical phonon modes are theoretically derived and compared with available experimental data. Our results confirm the recent phonon assignment proposed by Margueron et al. [J. Appl. Phys. 111, 104105 (2012)] on the basis of spectroscopical studies. A comparison with the phonon band structure of the related material LiNbO3 shows minor differences that can be traced to the atomic‐mass difference between Ta and Nb. The presence of phonons with imaginary frequencies for the paraelectric phase suggests that it does not correspond to a minimum energy structure, and is compatible with an order‐disorder type phase transition.

Vibrational properties ofLiNb1−xTaxO3mixed crystals

M. Rüsing, S. Sanna, S. Neufeld, G. Berth, W.G. Schmidt, A. Zrenner, H. Yu, Y. Wang, H. Zhang, Physical Review B (2016)

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Strain-induced quasi-one-dimensional rare-earth silicide structures on Si(111)

F. Timmer, R. Oelke, C. Dues, S. Sanna, W.G. Schmidt, M. Franz, S. Appelfeller, M. Dähne, J. Wollschläger, Physical Review B (2016), 94(20)

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Experimental and Theoretical High-Energy-Resolution X-ray Absorption Spectroscopy: Implications for the Investigation of the Entatic State

N.J. Vollmers, P. Müller, A. Hoffmann, S. Herres-Pawlis, M. Rohrmüller, W.G. Schmidt, U. Gerstmann, M. Bauer, Inorganic Chemistry (2016), 55, pp. 11694-11706

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Optical response of the Cu2S2diamond core in Cu2II(NGuaS)2Cl2

M. Witte, B. Grimm-Lebsanft, A. Goos, S. Binder, M. Rübhausen, M. Bernard, A. Neuba, S. Gorelsky, U. Gerstmann, G. Henkel, W.G. Schmidt, S. Herres-Pawlis, Journal of Computational Chemistry (2016), 37(23-24), pp. 2181-2192

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Surface vibrational Raman modes of In:Si(111)(4×1)and(8×2)nanowires

E. Speiser, N. Esser, S. Wippermann, W.G. Schmidt, Physical Review B (2016), 94(7)

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Temperature-Dependent Hole Mobility and Its Limit in Crystal-Phase P3HT Calculated from First Principles

A. Lücke, F. Ortmann, M. Panhans, S. Sanna, E. Rauls, U. Gerstmann, W.G. Schmidt, The Journal of Physical Chemistry B (2016), 120, pp. 5572-5580

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Inhomogeneous and Homogeneous Line Broadening of Optical Spectra of PTCDA Molecules Adsorbed at Step Edges of Alkali Halide Surfaces

A. Paulheim, C. Marquardt, H. Aldahhak, E. Rauls, W.G. Schmidt, M. Sokolowski, The Journal of Physical Chemistry C (2016), 10, pp. 11926-11937

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Grand canonical Peierls transition in In/Si(111)

E. Jeckelmann, S. Sanna, W.G. Schmidt, E. Speiser, N. Esser, Physical Review B (2016), 93(24)

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Rare-earth silicide thin films on the Si(111) surface

S. Sanna, C. Dues, W.G. Schmidt, F. Timmer, J. Wollschläger, M. Franz, S. Appelfeller, M. Dähne, Physical Review B (2016), 93(19)

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Density functional theory of the CuA-like Cu2S2 diamond core in Cu 2II(NGuaS)2Cl2

M. Witte, U. Gerstmann, A. Neuba, G. Henkel, W.G. Schmidt, Journal of Computational Chemistry (2016), 37, pp. 1005-1018

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Atomic size effects studied by transport in single silicide nanowires

I. Miccoli, F. Edler, H. Pfnür, S. Appelfeller, M. Dähne, K. Holtgrewe, S. Sanna, W.G. Schmidt, C. Tegenkamp, Physical Review B (2016)

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Manipulation resolves non-trivial structure of corrole monolayer on Ag(111)

S. Tebi, H. Aldahhak, G. Serrano, W. Schöfberger, E. Rauls, W.G. Schmidt, R. Koch, S. Müllegger, Nanotechnology (2016), 27, 025704

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Surface induced vibrational modes in the fluorescence spectra of PTCDA adsorbed on the KCl(100) and NaCl(100) surfaces

A. Paulheim, C. Marquardt, M. Sokolowski, M. Hochheim, T. Bredow, H. Aldahhak, E. Rauls, W.G. Schmidt, Physical Chemistry Chemical Physics (2016), 18, pp. 32891-32902

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<p>We report a combined experiment-theory study on low energy vibrational modes in fluorescence spectra of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) molecules.</p>

Impurity-Mediated Early Condensation of a Charge Density Wave in an Atomic Wire Array

H.W. Yeom, D.M. Oh, S. Wippermann, W.G. Schmidt, ACS Nano (2016), 10, pp. 810-814

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Bay-Extended, Distorted Perylene Esters Showing Visible Luminescence after Ultraviolet Excitation: Photophysical and Electrochemical Analysis

J. Vollbrecht, C. Wiebeler, A. Neuba, H. Bock, S. Schumacher, H. Kitzerow, The Journal of Physical Chemistry C (2016), pp. 7839-7848

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Ultrafast shift and rectification photocurrents in GaAs quantum wells: Excitation intensity dependence and the importance of band mixing

H.T. Duc, R. Podzimski, S. Priyadarshi, M. Bieler, T. Meier, Physical Review B (2016)

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Two-dimensional symbiotic solitons and vortices in binary condensates with attractive cross-species interaction

X. Ma, R. Driben, B.A. Malomed, T. Meier, S. Schumacher, Scientific Reports (2016), 6, 34847

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Ultrafast dynamical response of the lower exciton-polariton branch in CdZnTe

J. Lohrenz, S. Melzer, C. Ruppert, I.A. Akimov, H. Mariette, M. Reichelt, A. Trautmann, T. Meier, M. Betz, Physical Review B (2016), 93(7)

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Indium oxide inverse opal films synthesized by structure replication method

S. Amrehn, D. Berghoff, A. Nikitin, M. Reichelt, X. Wu, T. Meier, T. Wagner, Photonics and Nanostructures - Fundamentals and Applications (2016), 19, pp. 55-63

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Photocurrents in semiconductors and semiconductor quantum wells analyzed by k.p-based Bloch equations

R. Podzimski, H.T. Duc, S. Priyadarshi, C. Schmidt, M. Bieler, T. Meier, in: Ultrafast Phenomena and Nanophotonics XX, 2016

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Numerical investigation of turbulent forced convection heat transfer in pillow plates

M. Piper, A. Zibart, J. Tran, E. Kenig, International Journal of Heat and Mass Transfer (2015), pp. 516-527

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Optimierung der Kühlung eines On-Board-Ladegeräts für elektrisch betriebene Kraftfahrzeuge mithilfe der CFD-Methoden

A. Zibart, R. Cherkezova, H.. Figge, E. Kenig. Optimierung der Kühlung eines On-Board-Ladegeräts für elektrisch betriebene Kraftfahrzeuge mithilfe der CFD-Methoden. In: Jahrestreffen der ProcessNet-Fachgemeinschaft Fluiddynamik und Trenntechnik, Bamberg, 2015.

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How intermolecular geometrical disorder affects the molecular doping of donor–acceptor copolymers

D. Di Nuzzo, C. Fontanesi, R. Jones, S. Allard, I. Dumsch, U. Scherf, E. von Hauff, S. Schumacher, E. Da Como, Nature Communications (2015)

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A population-competition model for analyzing transverse optical patterns including optical control and structural anisotropy

Y.C. Tse, C.K.P. Chan, M.H. Luk, N.H. Kwong, P.T. Leung, R. Binder, S. Schumacher, New Journal of Physics (2015), 083054

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All-optical flow control of a polariton condensate using nonresonant excitation

J. Schmutzler, P. Lewandowski, M. Aßmann, D. Niemietz, S. Schumacher, M. Kamp, C. Schneider, S. Höfling, M. Bayer, Physical Review B (2015)

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Subpicosecond Exciton Dynamics in Polyfluorene Films from Experiment and Microscopic Theory

J. Denis, S. Schumacher, G.J. Hedley, A. Ruseckas, P.O. Morawska, Y. Wang, S. Allard, U. Scherf, G.A. Turnbull, I.D.W. Samuel, I. Galbraith, The Journal of Physical Chemistry C (2015), pp. 9734-9744

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Kennwertermittlung an Faserverbundkunststoffen für Crashsimulationen mit dem FE-Solver LS-Dyna

C. Reuter, T. Tröster, C. Lauter, Verlag Stahleisen GmbH, 2015, pp. 127-132

Efficient Biomimetic Hydroxylation Catalysis with a Bis(pyrazolyl)imidazolylmethane Copper Peroxide Complex

C. Wilfer, P. Liebhäuser, A. Hoffmann, H. Erdmann, O. Grossmann, L. Runtsch, E. Paffenholz, R. Schepper, R. Dick, M. Bauer, M. Dürr, I. Ivanović-Burmazović, S. Herres-Pawlis, Chemistry - A European Journal (2015), pp. 17639-17649

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Adaptive Playouts in Monte-Carlo Tree Search with Policy-Gradient Reinforcement Learning

T. Graf, M. Platzner, in: Advances in Computer Games: 14th International Conference, ACG 2015, Leiden, The Netherlands, July 1-3, 2015, Revised Selected Papers, Springer International Publishing, 2015, pp. 1-11

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Localization Length Index and Subleading Corrections in a Chalker-Coddington Model: A Numerical Study

W. Nuding, A. Klümper, A. Sedrakyan, Physical Review B (2015), 91, pp. 115107

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GaNm-plane: Atomic structure, surface bands, and optical response

M. Landmann, E. Rauls, W.G. Schmidt, M. Neumann, E. Speiser, N. Esser, Physical Review B (2015)

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Liquid Crystal (8CB) Molecular Adsorption on Lithium Niobate Z-Cut Surfaces

C. Braun, S. Sanna, W.G. Schmidt, The Journal of Physical Chemistry C (2015), pp. 9342-9346

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Phonon dispersion and zero-point renormalization of LiNbO3 from density-functional perturbation theory

M. Friedrich, A. Riefer, S. Sanna, W.G. Schmidt, A. Schindlmayr, Journal of Physics: Condensed Matter (2015), 27(38), 385402

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PubMed

The vibrational properties of stoichiometric LiNbO3 are analyzed within density-functional perturbation theory in order to obtain the complete phonon dispersion of the material. The phonon density of states of the ferroelectric (paraelectric) phase shows two (one) distinct band gaps separating the high-frequency (~800 cm−1) optical branches from the continuum of acoustic and lower optical phonon states. This result leads to specific heat capacites in close agreement with experimental measurements in the range 0–350 K and a Debye temperature of 574 K. The calculated zero-point renormalization of the electronic Kohn–Sham eigenvalues reveals a strong dependence on the phonon wave vectors, especially near Γ. Integrated over all phonon modes, our results indicate a vibrational correction of the electronic band gap of 0.41 eV at 0 K, which is in excellent agreement with the extrapolated temperature-dependent measurements.

Defect complexes in congruentLiNbO3and their optical signatures

Y. Li, W.G. Schmidt, S. Sanna, Physical Review B (2015)

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Raman scattering efficiency inLiTaO3andLiNbO3crystals

S. Sanna, S. Neufeld, M. Rüsing, G. Berth, A. Zrenner, W.G. Schmidt, Physical Review B (2015)

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Modeling atomic force microscopy at LiNbO 3 surfaces from first-principles

S. Sanna, C. Dues, W.G. Schmidt, Computational Materials Science (2015), pp. 145-150

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Mechanism for nuclear and electron spin excitation by radio frequency current

S. Müllegger, E. Rauls, U. Gerstmann, S. Tebi, G. Serrano, S. Wiespointner-Baumgarthuber, W.G. Schmidt, R. Koch, Physical Review B (2015), 92(22)

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Single PTCDA molecules on planar and stepped KCl and NaCl(100) surfaces

H. Aldahhak, W.G. Schmidt, E. Rauls, Surface Science (2015), pp. 278-281

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Diindenoperylene adsorption on Cu(111) studied with density-functional theory

H. Aldahhak, E. Rauls, W.G. Schmidt, Surface Science (2015), pp. 260-265

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Interwire coupling forIn(4×1)/Si(111) probed by surface transport

F. Edler, I. Miccoli, S. Demuth, H. Pfnür, S. Wippermann, A. Lücke, W.G. Schmidt, C. Tegenkamp, Physical Review B (2015), 92(8)

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Water adsorbate influence on the Cu(110) surface optical response

A. Baghbanpourasl, W.G. Schmidt, M. Denk, C. Cobet, M. Hohage, P. Zeppenfeld, K. Hingerl, Surface Science (2015), 641, pp. 231-236

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The Cu2O2torture track for a real-life system: [Cu2(btmgp)2O2]2+oxo and peroxo species in density functional calculations†

M. Rohrmüller, A. Hoffmann, C. Thierfelder, S. Herres-Pawlis, W.G. Schmidt, Journal of Computational Chemistry (2015), 36(21-22), pp. 1672-1685

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Influence of Structural Defects and Oxidation onto Hole Conductivity in P3HT

A. Lücke, W.G. Schmidt, E. Rauls, F. Ortmann, U. Gerstmann, The Journal of Physical Chemistry B (2015), 119, pp. 6481-6491

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Barrier-free subsurface incorporation of 3d metal atoms into Bi(111) films

C. Klein, N.J. Vollmers, U. Gerstmann, P. Zahl, D. Lükermann, G. Jnawali, H. Pfnür, C. Tegenkamp, P. Sutter, W.G. Schmidt, M. Horn-von Hoegen, Physical Review B (2015), 91(19)

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Modeling atomic force microscopy at LiNbO 3 surfaces from first-principles

S. Sanna, C. Dues, W.G. Schmidt, Computational Materials Science (2015), 103, pp. 145-150

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GaNm-plane: Atomic structure, surface bands, and optical response

M. Landmann, E. Rauls, W.G. Schmidt, M. Neumann, E. Speiser, N. Esser, Physical Review B (2015), 91

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A panel of peralkylated sulfur–guanidine type bases: Novel pro-ligands for use in biomimetic coordination chemistry

A. Neuba, M. Rohrmüller, R. Hölscher, W.G. Schmidt, G. Henkel, Inorganica Chimica Acta (2015), 430, pp. 225-238

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Curvature effects in the band structure of carbon nanotubes including spin–orbit coupling

H. Liu, D.F. Heinze, H. Thanh Duc, S. Schumacher, T. Meier, Journal of Physics: Condensed Matter (2015), 27, 445501

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Curvature effects in the band structure of carbon nanotubes including spin–orbit coupling

H. Liu, D.F. Heinze, H. Thanh Duc, S. Schumacher, T. Meier, Journal of Physics: Condensed Matter (2015), 445501

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Time-domain calculations of shift currents in bulk GaAs

R. Podzimski, H.T. Duc, T. Meier, in: Ultrafast Phenomena and Nanophotonics XIX, 2015

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Creation of vortices by torque in multidimensional media with inhomogeneous defocusing nonlinearity

R. Driben, T. Meier, B.A. Malomed, Scientific Reports (2015), 5, pp. 9420

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Optical Spectroscopy of Graphene Quantum Dots: The Case of C132

H. Riesen, C. Wiebeler, S. Schumacher, The Journal of Physical Chemistry A (2014), pp. 5189-5195

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Quantum Yields and Reaction Times of Photochromic Diarylethenes: Nonadiabatic Ab Initio Molecular Dynamics for Normal- and Inverse-Type

C. Wiebeler, S. Schumacher, The Journal of Physical Chemistry A (2014), pp. 7816-7823

DOI

Formation and control of transverse patterns in a quantum fluid of microcavity polaritons

P. Lewandowski, V. Ardizzone, Y.C. Tse, N.H. Kwong, M.H. Luk, A. Lücke, M. Abbarchi, J. Bloch, E. Baudin, E. Galopin, A. Lemaître, P.T. Leung, P. Roussignol, R. Binder, J. Tignon, S. Schumacher, in: Ultrafast Phenomena and Nanophotonics XVIII, 2014

DOI

Common Fate Graph Patterns in Monte Carlo Tree Search for Computer Go

T. Graf, M. Platzner, in: 2014 IEEE Conference on Computational Intelligence and Games, 2014, pp. 1-8

DOI

Modeling intrinsic defects in LiNbO3 within the Slater-Janak transition state model

Y. Li, S. Sanna, W.G. Schmidt, The Journal of Chemical Physics (2014), 234113

DOI

Modeling LiNbO3 Surfaces at Ambient Conditions

R. Hölscher, W.G. Schmidt, S. Sanna, The Journal of Physical Chemistry C (2014), pp. 10213-10220

DOI

Adsorption of PTCDA on Terraces and at Steps Sites of the KCl(100) Surface

Q. Guo, A. Paulheim, M. Sokolowski, H. Aldahhak, E. Rauls, W.G. Schmidt, The Journal of Physical Chemistry C (2014), 118, pp. 29911-29918

DOI

Oxygen adsorbates on the Si(111)4×1-In metallic atomic wire: Scanning tunneling microscopy and density-functional theory calculations

D.M. Oh, S. Wippermann, W.G. Schmidt, H.W. Yeom, Physical Review B (2014), 90(15)

DOI

Geometrical and optical benchmarking of copper(II) guanidine-quinoline complexes: Insights from TD-DFT and many-body perturbation theory (part II)

A. Hoffmann, M. Rohrmüller, A. Jesser, I. dos Santos Vieira, W.G. Schmidt, S. Herres-Pawlis, Journal of Computational Chemistry (2014), 35(29-30), pp. 2146-2161

DOI

The atomic structure of ternary amorphous TixSi1−xO2hybrid oxides

M. Landmann, T. Köhler, E. Rauls, T. Frauenheim, W.G. Schmidt, Journal of Physics: Condensed Matter (2014), 26, 253201

DOI

Rashba splitting and relativistic energy shifts in In/Si(111) nanowires

U. Gerstmann, N.J. Vollmers, A. Lücke, M. Babilon, W.G. Schmidt, Physical Review B (2014), 89(16)

DOI

Temperature dependent LiNbO3(0001): Surface reconstruction and surface charge

S. Sanna, R. Hölscher, W.G. Schmidt, Applied Surface Science (2014), pp. 70-78

DOI

Unraveling theLiNbO3X-cut surface by atomic force microscopy and density functional theory

S. Sanna, W.G. Schmidt, S. Rode, S. Klassen, A. Kühnle, Physical Review B (2014), 89(7)

DOI

Polycyclic Aromatic Hydrocarbons Obtained by Lateral Core Extension of Mesogenic Perylenes: Absorption and Optoelectronic Properties

J. Vollbrecht, H. Bock, C. Wiebeler, S. Schumacher, H. Kitzerow, Chemistry - A European Journal (2014), pp. 12026-12031

DOI

Influence of Coulomb-induced band couplings on linear excitonic absorption spectra of semiconducting carbon nanotubes

H. Liu, S. Schumacher, T. Meier, Physical Review B (2014)

DOI

Regeneration of Airy pulses in fiber-optic links with dispersion management of the two leading dispersion terms of opposite signs

R. Driben, T. Meier, Physical Review A (2014)

DOI

Nonlinear dynamics of Airy-vortex 3D wave packets: emission of vortex light waves

R. Driben, T. Meier, Optics Letters (2014), 5539

DOI

Coupled Airy breathers

R. Driben, V.V. Konotop, T. Meier, Optics Letters (2014), 5523

DOI

Lithium niobate dielectric function and second-order polarizability tensor from massively parallel ab initio calculations

A. Riefer, M. Rohrmüller, M. Landmann, S. Sanna, E. Rauls, N.J. Vollmers, R. Hölscher, M. Witte, Y. Li, U. Gerstmann, A. Schindlmayr, W.G. Schmidt, in: High Performance Computing in Science and Engineering ‘13, Springer, 2013, pp. 93-104

Abstract

DOI

WoS

The frequency-dependent dielectric function and the second-order polarizability tensor of ferroelectric LiNbO3 are calculated from first principles. The calculations are based on the electronic structure obtained from density-functional theory. The subsequent application of the GW approximation to account for quasiparticle effects and the solution of the Bethe–Salpeter equation yield a dielectric function for the stoichiometric material that slightly overestimates the absorption onset and the oscillator strength in comparison with experimental measurements. Calculations at the level of the independent-particle approximation indicate that these deficiencies are at least partially related to the neglect of intrinsic defects typical for the congruent material. The second-order polarizability calculated within the independent-particle approximation predicts strong nonlinear coefficients for photon energies above 1.5 eV. The comparison with measured data suggests that self-energy effects improve the agreement between experiment and theory. The intrinsic defects of congruent samples reduce the optical nonlinearities, in particular for the 21 and 31 tensor components, further improving the agreement with measured data.

Formation and control of Turing patterns in a coherent quantum fluid

V. Ardizzone, P. Lewandowski, M.H. Luk, Y.C. Tse, N.H. Kwong, A. Lücke, M. Abbarchi, E. Baudin, E. Galopin, J. Bloch, A. Lemaitre, P.T. Leung, P. Roussignol, R. Binder, J. Tignon, S. Schumacher, Scientific Reports (2013)

DOI

Charge Photogeneration in Donor–Acceptor Conjugated Materials: Influence of Excess Excitation Energy and Chain Length

R. Tautz, E. Da Como, C. Wiebeler, G. Soavi, I. Dumsch, N. Fröhlich, G. Grancini, S. Allard, U. Scherf, G. Cerullo, S. Schumacher, J. Feldmann, Journal of the American Chemical Society (2013), pp. 4282-4290

DOI

Transverse optical instability patterns in semiconductor microcavities: Polariton scattering and low-intensity all-optical switching

M.H. Luk, Y.C. Tse, N.H. Kwong, P.T. Leung, P. Lewandowski, R. Binder, S. Schumacher, Physical Review B (2013)

DOI

Excited-State Absorption of Conjugated Polymers in the Near-Infrared and Visible: A Computational Study of Oligofluorenes

S. Ling, S. Schumacher, I. Galbraith, M.J. Paterson, The Journal of Physical Chemistry C (2013), pp. 6889-6895

DOI

Geometrical and optical benchmarking of copper guanidine-quinoline complexes: Insights from TD-DFT and many-body perturbation theory†

A. Jesser, M. Rohrmüller, W.G. Schmidt, S. Herres-Pawlis, Journal of Computational Chemistry (2013), 35(1-2), pp. 1-17

DOI

LiNb1-xTaxO3Electronic Structure and Optical Response fromFirst-PrinciplesCalculations

A. Riefer, S. Sanna, W.G. Schmidt, Ferroelectrics (2013), 447, pp. 78-85

DOI

Vibrational Fingerprints of LiNbO3-LiTaO3Mixed Crystals

S. Sanna, A. Riefer, S. Neufeld, W.G. Schmidt, G. Berth, M. Rüsing, A. Widhalm, A. Zrenner, Ferroelectrics (2013), 447, pp. 63-68

DOI

Charge compensation by long-period reconstruction in strongly polar lithium niobate surfaces

S. Sanna, S. Rode, R. Hölscher, S. Klassen, C. Marutschke, K. Kobayashi, H. Yamada, W.G. Schmidt, A. Kühnle, Physical Review B (2013), 88

DOI

Adsorption of PTCDA on NaCl(100) and KCl(100)

H. Aldahhak, W.G. Schmidt, E. Rauls, Surface Science (2013), 617, pp. 242-248

DOI

Optical response of stoichiometric and congruent lithium niobate from first-principles calculations

A. Riefer, S. Sanna, A. Schindlmayr, W.G. Schmidt, Physical Review B (2013), 87(19), 195208

Abstract

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DOI

WoS

The frequency-dependent dielectric function and the second-order polarizability tensor of ferroelectric LiNbO3 are calculated from first principles. The calculations are based on the electronic structure obtained from density-functional theory. The subsequent application of the GW approximation to account for quasiparticle effects and the solution of the Bethe-Salpeter equation for the stoichiometric material yield a dielectric function that slightly overestimates the absorption onset and the oscillator strength in comparison with experimental measurements. Calculations at the level of the independent-particle approximation indicate that these deficiencies are, at least, partially related to the neglect of intrinsic defects typical for the congruent material. The second-order polarizability calculated within the independent-particle approximation predicts strong nonlinear coefficients for photon energies above 1.5 eV. The comparison with measured data suggests that the inclusion of self-energy effects in the nonlinear optical response leads to a better agreement with experiments. The intrinsic defects of congruent samples reduce the optical nonlinearities, in particular, for the 21 and 31 tensor components, further improving the agreement between experiments and theory.

PhysRevB.87.195208.pdf - © 2013 American Physical…

Bis-μ-oxo and μ-η2:η2-peroxo dicopper complexes studied within (time-dependent) density-functional and many-body perturbation theory

M. Rohrmüller, S. Herres-Pawlis, M. Witte, W.G. Schmidt, Journal of Computational Chemistry (2013), 34, pp. 1035-1045

DOI

Atomic Structure of Interface States in Silicon Heterojunction Solar Cells

B.M. George, J. Behrends, A. Schnegg, T.F. Schulze, M. Fehr, L. Korte, B. Rech, K. Lips, M. Rohrmüller, E. Rauls, W.G. Schmidt, U. Gerstmann, Physical Review Letters (2013), 110(13)

DOI

LiNb1-xTaxO3Electronic Structure and Optical Response fromFirst-PrinciplesCalculations

A. Riefer, S. Sanna, W.G. Schmidt, Ferroelectrics (2013), 447, pp. 78-85

DOI

Selection rules and linear absorption spectra of carbon nanotubes in axial magnetic fields

H. Liu, S. Schumacher, T. Meier, Physical Review B (2013)

DOI

Spectral Signatures of Polarons in Conjugated Co-polymers

C. Wiebeler, R. Tautz, J. Feldmann, E. von Hauff, E. Da Como, S. Schumacher, The Journal of Physical Chemistry B (2012), pp. 4454-4460

DOI

Dynamics of fluorescence depolarisation in star-shaped oligofluorene-truxene molecules

N.A. Montgomery, G.J. Hedley, A. Ruseckas, J. Denis, S. Schumacher, A.L. Kanibolotsky, P.J. Skabara, I. Galbraith, G.A. Turnbull, I.D.W. Samuel, Physical Chemistry Chemical Physics (2012), 9176

DOI

Simulation and testing of hybrid structures consisting of press-hardened steel and CFRP

C. Reuter, M. Frantz, C. Lauter, H. Block, T. Tröster, 2012

Simulation and manufacturing of deep drawn parts reinforced by carbon fibre prepregs

B. Gorny, F. Hankeln, C. Lauter, H.C. Schmidt, U. Damerow, R. Mahnken, H.J. Maier, T. Tröster, W. Homberg, 2012

Crash tests of hybrid structures consisting of sheet metal and local CFRP reinforcements

C. Lauter, M. Frantz, J.P. Kohler, T. Tröster, 2012

Substrate Induced Thermal Decomposition of Perfluoro-Pentacene Thin Films on the Coinage Metals

C. Schmidt, T. Breuer, S. Wippermann, W.G. Schmidt, G. Witte, The Journal of Physical Chemistry C (2012), 116, pp. 24098-24106

DOI

Atomistic Picture of Charge Density Wave Formation at Surfaces

S. Wall, B. Krenzer, S. Wippermann, S. Sanna, F. Klasing, A. Hanisch-Blicharski, M. Kammler, W.G. Schmidt, M. Horn-von Hoegen, Physical Review Letters (2012), 109(18)

DOI

Ferroelectric phase transition in LiNbO3: Insights from molecular dynamics

S. Sanna, W.G. Schmidt, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control (2012), 59(9), pp. 1925-1928

DOI

Linear and nonlinear optical response of LiNbO3 calculated from first principles

A. Riefer, S. Sanna, A.V. Gavrilenko, W.G. Schmidt, IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control (2012), 59(9), pp. 1929-1933

DOI

Polarization-dependent methanol adsorption on lithium niobate Z-cut surfaces

A. Riefer, S. Sanna, W.G. Schmidt, Physical Review B (2012), 86(12)

DOI

Atomic-resolution imaging of the polar (0001¯) surface of LiNbO3in aqueous solution by frequency modulation atomic force microscopy

S. Rode, R. Hölscher, S. Sanna, S. Klassen, K. Kobayashi, H. Yamada, W.G. Schmidt, A. Kühnle, Physical Review B (2012), 86(7)

DOI

Fingerprints of order and disorder in the electronic and optical properties of crystalline and amorphous TiO2

M. Landmann, T. Köhler, S. Köppen, E. Rauls, T. Frauenheim, W.G. Schmidt, Physical Review B (2012), 86(6)

DOI

Interplay between metal-free phthalocyanine molecules and Au(110) substrates

E. Rauls, W.G. Schmidt, T. Pertram, K. Wandelt, Surface Science (2012), 606, pp. 1120-1125

DOI

The electronic structure and optical response of rutile, anatase and brookite TiO2

M. Landmann, E. Rauls, W.G. Schmidt, Journal of Physics: Condensed Matter (2012), 24, 195503

DOI

2-Aminopyrimidine-silver(I) based organic semiconductors: Electronic structure and optical response

A. Riefer, E. Rauls, W.G. Schmidt, J. Eberhard, I. Stoll, J. Mattay, Physical Review B (2012), 85(16)

DOI

pH-dependent structure and energetics of H2O/MgO(100)

P. Thissen, V. Thissen, S. Wippermann, Y.J. Chabal, G. Grundmeier, W.G. Schmidt, Surface Science (2012), 606, pp. 902-907

DOI

Adsorption of OH and H at the LiNbO3(0001) surface

R. Hölscher, S. Sanna, W.G. Schmidt, physica status solidi (c) (2012), 9(6), pp. 1361-1365

DOI

In-Si(111)(4 × 1)/(8 × 2) nanowires: Electron transport, entropy, and metal-insulator transition

W.G. Schmidt, S. Wippermann, S. Sanna, M. Babilon, N.J. Vollmers, U. Gerstmann, physica status solidi (b) (2012), 249(2), pp. 343-359

DOI

Cavity-assisted emission of polarization-entangled photons from biexcitons in quantum dots with fine-structure splitting

S. Schumacher, J. Förstner, A. Zrenner, M. Florian, C. Gies, P. Gartner, F. Jahnke, Optics Express (2012), 20(5), pp. 5335-5342

Abstract

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DOI

We study the quantum properties and statistics of photons emitted by a quantum-dot biexciton inside a cavity. In the biexciton-exciton cascade, fine-structure splitting between exciton levels degrades polarization-entanglement for the emitted pair of photons. However, here we show that the polarization-entanglement can be preserved in such a system through simultaneous emission of two degenerate photons into cavity modes tuned to half the biexciton energy. Based on detailed theoretical calculations for realistic quantum-dot and cavity parameters, we quantify the degree of achievable entanglement.

2012 Schumacher,Förstner,Zrenner,Florian,Gies,Gartner,Jahnke_Cavity assisted emission of polarization-entangled photons.pdf -

Tailoring the high-harmonic emission in two-level systems and semiconductors by pulse shaping

M. Reichelt, A. Walther, T. Meier, Journal of the Optical Society of America B (2012), A36

DOI

Influence of Na adsorption on the quantum conductance and metal-insulator transition of the In-Si(111)(4×1)–(8×2) nanowire array

W.G. Schmidt, M. Babilon, C. Thierfelder, S. Sanna, S. Wippermann, Physical Review B (2011), 84(11)

DOI

Group-VII point defects in ZnSe

L.S. dos Santos, W.G. Schmidt, E. Rauls, Physical Review B (2011), 84(11)

DOI

Preserving Charge and Oxidation State of Au(III) Ions in an Agent-Functionalized Nanocrystal Model System

S. Müllegger, W. Schöfberger, M. Rashidi, T. Lengauer, F. Klappenberger, K. Diller, K. Kara, J.V. Barth, E. Rauls, W.G. Schmidt, R. Koch, ACS Nano (2011), 5(8), pp. 6480-6486

DOI

Band offsets in cubic GaN/AlN superlattices

C. Mietze, M. Landmann, E. Rauls, H. Machhadani, S. Sakr, M. Tchernycheva, F.H. Julien, W.G. Schmidt, K. Lischka, D.J. As, Physical Review B (2011), 83(19)

DOI

Asymmetric saddling of single porphyrin molecules on Au(111)

S. Müllegger, M. Rashidi, T. Lengauer, E. Rauls, W.G. Schmidt, G. Knör, W. Schöfberger, R. Koch, Physical Review B (2011), 83(16)

DOI

Methane adsorption on graphene from first principles including dispersion interaction

C. Thierfelder, M. Witte, S. Blankenburg, E. Rauls, W.G. Schmidt, Surface Science (2011), 605, pp. 746-749

DOI

Localised Phonon Modes at LiNbO3(0001) Surfaces

S. Sanna, G. Berth, W. Hahn, A. Widhalm, A. Zrenner, W.G. Schmidt, Ferroelectrics (2011), 419, pp. 1-8

DOI

Vibrational properties of the LiNbO3 z-surfaces

S. Sanna, G. Berth, W. Hahn, A. Widhalm, A. Zrenner, W.G. Schmidt, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control (2011), 58(9), pp. 1751-1756

DOI

Barium titanate ground- and excited-state properties from first-principles calculations

S. Sanna, C. Thierfelder, S. Wippermann, T.P. Sinha, W.G. Schmidt, Physical Review B (2011), 83(5)

DOI

Dynamics of photoexcitation and stimulated optical emission in conjugated polymers: A multiscale quantum-chemistry and Maxwell-Bloch-equations approach

S. Schumacher, I. Galbraith, A. Ruseckas, G.A. Turnbull, I.D.W. Samuel, Physical Review B (2010)

DOI

Do we know the band gap of lithium niobate?

C. Thierfelder, S. Sanna, A. Schindlmayr, W.G. Schmidt, Physica Status Solidi C (2010), 7(2), pp. 362-365

Abstract

DOI

WoS

Given the vast range of lithium niobate (LiNbO3) applications, the knowledge about its electronic and optical properties is surprisingly limited. The direct band gap of 3.7 eV for the ferroelectric phase – frequently cited in the literature – is concluded from optical experiments. Recent theoretical investigations show that the electronic band‐structure and optical properties are very sensitive to quasiparticle and electron‐hole attraction effects, which were included using the GW approximation for the electron self‐energy and the Bethe‐Salpeter equation respectively, both based on a model screening function. The calculated fundamental gap was found to be at least 1 eV larger than the experimental value. To resolve this discrepancy we performed first‐principles GW calculations for lithium niobate using the full‐potential linearized augmented plane‐wave (FLAPW) method. Thereby we use the parameter‐free random phase approximation for a realistic description of the nonlocal and energydependent screening. This leads to a band gap of about 4.7 (4.2) eV for ferro(para)‐electric lithium niobate.

Ab initiog-tensor calculation for paramagnetic surface states: hydrogen adsorption at Si surfaces

U. Gerstmann, M. Rohrmüller, F. Mauri, W.G. Schmidt, physica status solidi (c) (2010), 7(2), pp. 157-160

DOI

Optical anisotropy of Si(111)-(4 × 1)/(8 × 2)-In nanowires calculated fromfirst-principles

S. Wippermann, W.G. Schmidt, F. Bechstedt, S. Chandola, K. Hinrichs, M. Gensch, N. Esser, K. Fleischer, J.F. McGilp, physica status solidi (c) (2010), 7(2), pp. 133-136

DOI

Catalytic Action of a Cu(111) Surface on Tetraazaperopyrene Polymerization

S. Blankenburg, E. Rauls, W.G. Schmidt, The Journal of Physical Chemistry Letters (2010), 1, pp. 3266-3270

DOI

Entropy Explains Metal-Insulator Transition of the Si(111)-In Nanowire Array

S. Wippermann, W.G. Schmidt, Physical Review Letters (2010), 105(12)

DOI

First-principles investigation of CO adsorption on Pt/Ge(001)-(4×2)

A. Krivosheeva, S. Sanna, W.G. Schmidt, Computational Materials Science (2010), 49(4), pp. 895-898

DOI

Understanding the cubic AlN growth plane from first principles

E. Rauls, J. Wiebe, W.G. Schmidt, Journal of Crystal Growth (2010), 312, pp. 2892-2895

DOI

First-principles study of water adsorption and a high-density interfacial ice structure on(1×1)-O/Rh(111)

C. Thierfelder, W.G. Schmidt, Physical Review B (2010), 82(11)

DOI

Lithium niobateX-cut,Y-cut, andZ-cut surfaces fromab initiotheory

S. Sanna, W.G. Schmidt, Physical Review B (2010), 81(21)

DOI

GaN/LiNbO3 (0001) interface formation calculated from first-principles

S. Sanna, W.G. Schmidt, Applied Surface Science (2010), 256, pp. 5740-5743

DOI

Chemical reactivity on surfaces: Modeling the imide synthesis from DATP and PTCDA on Au(111)

E. Rauls, S. Blankenburg, W.G. Schmidt, Physical Review B (2010), 81(12)

DOI

GaN growth on LiNbO3 (0001) - a first-principles simulation

S. Sanna, W.G. Schmidt, physica status solidi (c) (2010), 7(7-8), pp. 2272-2274

DOI

Temperature dependent stability of self-assembled molecular rows

S. Blankenburg, W.G. Schmidt, physica status solidi (c) (2010), 7(2), pp. 415-417

DOI

The physics of highly ordered molecular rows

S. Blankenburg, E. Rauls, W.G. Schmidt, physica status solidi (c) (2010), 7(2), pp. 153-156

DOI

Ab initio investigation of the LiNbO3(0001) surface

S. Sanna, A.V. Gavrilenko, W.G. Schmidt, physica status solidi (c) (2010), 7(2), pp. 145-148

DOI

Dissociative and molecular adsorption of water onα-Al2O3(0001)

S. Wippermann, W.G. Schmidt, P. Thissen, G. Grundmeier, physica status solidi (c) (2010), 7(2), pp. 137-140

DOI

Tuning quantum-dot based photonic devices with liquid crystals

K.A. Piegdon, S. Declair, J. Förstner, T. Meier, H. Matthias, M. Urbanski, H. Kitzerow, D. Reuter, A.D. Wieck, A. Lorke, C. Meier, Optics Express (2010), 18(8), 7946

Abstract

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DOI

Microdisks made from GaAs with embedded InAs quantum dots are immersed in the liquid crystal 4-cyano-4’-pentylbiphenyl (5CB). The quantum dots serve as emitters feeding the optical modes of the photonic cavity. By changing temperature, the liquid crystal undergoes a phase transition from the isotropic to the nematic state, which can be used as an effective tuning mechanism of the photonic modes of the cavity. In the nematic state, the uniaxial electrical anisotropy of the liquid crystal molecules can be exploited for orienting the material in an electric field, thus externally controlling the birefringence of the material. Using this effect, an electric field induced tuning of the modes is achieved. Numerical simulations using the finite-differences time-domain (FDTD) technique employing an anisotropic dielectric medium allow to understand the alignment of the liquid crystal molecules on the surface of the microdisk resonator.

2010 Piegdon,Declair,Förstner,Meier T,Matthias,Urbanski,Kitzerow,Reuter,Wieck,Lorcke,Meier C_Tuning quantum-dot based photonic devices with liquid crystals.pdf -

Reversal of Coherently Controlled Ultrafast Photocurrents by Band Mixing in Undoped GaAs Quantum Wells

S. Priyadarshi, A.M. Racu, K. Pierz, U. Siegner, M. Bieler, H.T. Duc, J. Förstner, T. Meier, Physical Review Letters (2010), 104(21), 217401

Abstract

DOI

It is demonstrated that valence-band mixing in GaAs quantum wells tremendously modifies electronic transport. A coherent control scheme in which ultrafast currents are optically injected into undoped GaAs quantum wells upon excitation with femtosecond laser pulses is employed. An oscillatory dependence of the injection current amplitude and direction on the excitation photon energy is observed. A microscopic theoretical analysis shows that this current reversal is caused by the coupling of the light- and heavy-hole bands and that the hole currents dominate the overall current response. These surprising consequences of band mixing illuminate fundamental physics as they are unique for experiments which are able to monitor electronic transport resulting from carriers with relatively large momenta.

Electron-Spin Beat Susceptibility of Excitons in Semiconductor Quantum Wells

N.H. Kwong, S. Schumacher, R. Binder, Physical Review Letters (2009)

DOI

The physics of highly ordered molecular rows

S. Blankenburg, E. Rauls, W.G. Schmidt, physica status solidi (c) (2009), pp. 153-156

DOI

The physics of highly ordered molecular rows

S. Blankenburg, E. Rauls, W.G. Schmidt, physica status solidi (c) (2009), 7(2), pp. 153-156

DOI

Ab initioinvestigation of the LiNbO3(0001) surface

S. Sanna, A.V. Gavrilenko, W.G. Schmidt, physica status solidi (c) (2009), pp. 145-148

DOI

Ab initioinvestigation of the LiNbO3(0001) surface

S. Sanna, A.V. Gavrilenko, W.G. Schmidt, physica status solidi (c) (2009), 7(2), pp. 145-148

DOI

Dissociative and molecular adsorption of water onα-Al2O3(0001)

S. Wippermann, W.G. Schmidt, P. Thissen, G. Grundmeier, physica status solidi (c) (2009), 7(2), pp. 137-140

DOI

Vacancy clusters created via room temperature irradiation in 6H-SiC

A. Scholle, S. Greulich-Weber, E. Rauls, W.G. Schmidt, U. Gerstmann, Physica B: Condensed Matter (2009), 404, pp. 4742-4744

DOI

Water adsorption on the α-Al2O3(0001) surface

P. Thissen, G. Grundmeier, S. Wippermann, W.G. Schmidt, Physical Review B (2009), 80(24)

DOI

Rare-earth defect pairs in GaN: LDA+U calculations

S. Sanna, W.G. Schmidt, T. Frauenheim, U. Gerstmann, Physical Review B (2009), 80(10)

DOI

Role of Dihydrogen Bonds for the Stabilization of Self-Assembled Molecular Nanostructures

S. Blankenburg, E. Rauls, W.G. Schmidt, The Journal of Physical Chemistry C (2009), 113, pp. 12653-12657

DOI

Structure of Si(111)-In Nanowires Determined from the Midinfrared Optical Response

S. Chandola, K. Hinrichs, M. Gensch, N. Esser, S. Wippermann, W.G. Schmidt, F. Bechstedt, K. Fleischer, J.F. McGilp, Physical Review Letters (2009), 102(22)

DOI

Glutamic acid adsorbed on Ag(110): direct and indirect molecular interactions

S. Blankenburg, W.G. Schmidt, Journal of Physics: Condensed Matter (2009), 21, 185001

DOI

Water adsorption on hydrogenated Si(111) surfaces

B. Lange, R. Posner, K. Pohl, C. Thierfelder, G. Grundmeier, S. Blankenburg, W.G. Schmidt, Surface Science (2009), 603, pp. 60-64

DOI

First-principles calculations of clean Au(110) surfaces and chemisorption of atomic oxygen

M. Landmann, E. Rauls, W.G. Schmidt, Physical Review B (2009), 79(4)

DOI

QUANTUM ESPRESSO: a modular and open-source software project for quantum simulations of materials

P. Giannozzi, S. Baroni, N. Bonini, M. Calandra, R. Car, C. Cavazzoni, D. Ceresoli, G.L. Chiarotti, M. Cococcioni, I. Dabo, A. Dal Corso, S. de Gironcoli, S. Fabris, G. Fratesi, R. Gebauer, U. Gerstmann, C. Gougoussis, A. Kokalj, M. Lazzeri, L. Martin-Samos, N. Marzari, F. Mauri, R. Mazzarello, S. Paolini, A. Pasquarello, L. Paulatto, C. Sbraccia, S. Scandolo, G. Sclauzero, A.P. Seitsonen, A. Smogunov, P. Umari, R.M. Wentzcovitch, Journal of Physics: Condensed Matter (2009), 21(39), 395502

DOI

Optical anisotropy of the In/Si(111)(4×1)/(8×2) nanowire array

S. Wippermann, W.G. Schmidt, Surface Science (2008), 603, pp. 247-250

DOI

Water adsorption on clean Ni(111) and p(2×2)-Ni(111)-O surfaces calculated from first principles

S. Wippermann, W.G. Schmidt, Physical Review B (2008), 78(23)

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Spatial modulation of molecular adsorption energies due to indirect interaction

S. Blankenburg, W.G. Schmidt, Physical Review B (2008), 78

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Influence of the Side Group Aromaticity on the Organic Molecule Adsorption on Cu(110)

E. Rauls, W.G. Schmidt, Journal of Physical Chemistry C (2008), 112, pp. 11490-11494

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Atomic structure and energetics of thec-GaN(001) surface

E. Rauls, S.J. Dijkstra, W.G. Schmidt, Physical Review B (2008), 78(11)

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DFT calculations of adenine adsorption on coin metal (110) surfaces

E. Rauls, S. Blankenburg, W.G. Schmidt, Surface Science (2008), 602, pp. 2170-2174

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Resolving the Optical Spectrum of Water: Coordination and Electrostatic Effects

A. Hermann, W.G. Schmidt, P. Schwerdtfeger, Physical Review Letters (2008), 100(20)

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Theoretical study of the localization of excess electrons at the surface of ice

A. Hermann, P. Schwerdtfeger, W.G. Schmidt, Journal of Physics: Condensed Matter (2008), 20, 225003

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Adatom-Induced Conductance Modification of In Nanowires: Potential-Well Scattering and Structural Effects

S. Wippermann, N. Koch, W.G. Schmidt, Physical Review Letters (2008), 100(10)

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Ammonia adsorption on Cl/Si(001): First-principles calculations

B. Lange, W.G. Schmidt, Surface Science (2008), 602, pp. 1207-1211

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LiNbO3ground- and excited-state properties from first-principles calculations

W.G. Schmidt, M. Albrecht, S. Wippermann, S. Blankenburg, E. Rauls, F. Fuchs, C. Rödl, J. Furthmüller, A. Hermann, Physical Review B (2008), 77

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Ethanol adsorbed on ice: A first-principles study

C. Thierfelder, W.G. Schmidt, Physical Review B (2007), 76(19)

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Long-Range Chiral Recognition due to Substrate Locking and Substrate-Adsorbate Charge Transfer

S. Blankenburg, W.G. Schmidt, Physical Review Letters (2007), 99(19)

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Steric effects and chirality in the adsorption of glycine and phenylglycine on Cu(110)

S. Blankenburg, W.G. Schmidt, Nanotechnology (2007), 18, 424030

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Quantum conductance of In nanowires on Si(111) from first principles calculations

S. Wippermann, W.G. Schmidt, A. Calzolari, M.B. Nardelli, A. Stekolnikov, K. Seino, F. Bechstedt, Surface Science (2007), pp. 4045-4047

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Hexagon versus Trimer Formation in In Nanowires on Si(111): Energetics and Quantum Conductance

A.A. Stekolnikov, K. Seino, F. Bechstedt, S. Wippermann, W.G. Schmidt, A. Calzolari, M.B. Nardelli, Physical Review Letters (2007), 98(2)

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Tight-binding model for semiconductor quantum dots with a wurtzite crystal structure: From one-particle properties to Coulomb correlations and optical spectra

S. Schulz, S. Schumacher, G. Czycholl, Physical Review B (2006)

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Experimental and theoretical evidence for a hydrogen stabilizedc(2×2)reconstruction of the P-rich InP(001) surface

T. Letzig, F. Willig, P.H. Hahn, W.G. Schmidt, Physical Review B (2006), 74(24)

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Adsorption of phenylglycine on copper: Density functional calculations

S. Blankenburg, W.G. Schmidt, Physical Review B (2006), 74(15)

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Strongly bonded water monomers on the ice Ih basal plane: Density-functional calculations

C. Thierfelder, A. Hermann, P. Schwerdtfeger, W.G. Schmidt, Physical Review B (2006), 74(4)

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Adsorption of water on chlorine-terminated Si(111) from first principles: Substrate-induced ordering versus intermolecular interactions

S. Biering, A. Hermann, W.G. Schmidt, Physical Review B (2006), 73(23)

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Polariton propagation in shallow-confinement heterostructures: Microscopic theory and experiment showing the breakdown of the dead-layer concept

S. Schumacher, G. Czycholl, F. Jahnke, I. Kudyk, H.I. Rückmann, J. Gutowski, A. Gust, G. Alexe, D. Hommel, Physical Review B (2005)

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Coherent propagation of polaritons in semiconductor heterostructures: Nonlinear pulse transmission in theory and experiment

S. Schumacher, G. Czycholl, F. Jahnke, I. Kudyk, L. Wischmeier, I. Rückmann, T. Voss, J. Gutowski, A. Gust, D. Hommel, Physical Review B (2005)

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Interplay of surface reconstruction and surface electric fields in the optical anisotropy of GaAs(001)

W.G. Schmidt, F. Bechstedt, W. Lu, J. Bernholc, Physical Review B (2002), 66, pp. 0855334

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Large-Scale SCI Clusters in Practice: Architecture and Performance in SCI

J. Simon, A. Reinefeld, O. Heinz, in: SCI: Scalable Coherent Interface. Architecture and Software for High-Performance Compute Clusters, Springer, 1999, pp. 367-381

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