TY  - JOUR
A1  - Döring, Sebastian
A1  - Kollosche, Matthias
A1  - Rabe, Torsten
A1  - Stumpe, Joachim
A1  - Kofod, Guggi
T1  - Electrically tunable polymer DFB laser
JF  - Advanced materials
Y1  - 2011
U6  - https://doi.org/10.1002/adma.201102465
SN  - 0935-9648
VL  - 23
IS  - 37
SP  - 4265
EP  - 4269
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Blaha, Karen A.
A1  - Pikovskij, Arkadij
A1  - Rosenblum, Michael
A1  - Clark, Matthew T.
A1  - Rusin, Craig G.
A1  - Hudson, John L.
T1  - Reconstruction of two-dimensional phase dynamics from experiments on coupled oscillators
JF  - Physical review : E, Statistical, nonlinear and soft matter physics
N2  - Phase models are a powerful method to quantify the coupled dynamics of nonlinear oscillators from measured data. We use two phase modeling methods to quantify the dynamics of pairs of coupled electrochemical oscillators, based on the phases of the two oscillators independently and the phase difference, respectively. We discuss the benefits of the two-dimensional approach relative to the one-dimensional approach using phase difference. We quantify the dependence of the coupling functions on the coupling magnitude and coupling time delay. We show differences in synchronization predictions of the two models using a toy model. We show that the two-dimensional approach reveals behavior not detected by the one-dimensional model in a driven experimental oscillator. This approach is broadly applicable to quantify interactions between nonlinear oscillators, especially where intrinsic oscillator sensitivity and coupling evolve with time.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevE.84.046201
SN  - 1539-3755
VL  - 84
IS  - 4
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Tremblay, Jean Christophe
A1  - Monturet, Serge
A1  - Saalfrank, Peter
T1  - The Effects of electron-hole pair coupling on the infrared laser-controlled vibrational excitation of NO on Au(111)
JF  - The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment & general theory
N2  - In this work, we present theoretical simulations of laser-driven vibrational control of NO adsorbed on a gold surface. Our goal is to tailor laser pulses to selectively excite specific modes and vibrational eigenstates, as well as to favor photodesorption of the adsorbed molecule. To this end, various control schemes and algorithms are applied. For adsorbates at metallic surfaces, the creation of electron hole pairs in the substrate is known to play a dominant role in the transfer of energy from the system to the surroundings. These nonadiabatic couplings are included perturbatively in our reduced density matrix simulations using a generalization of the state-resolved position-dependent anharmonic rate model we recently introduced. An extension of the reduced density matrix is also proposed to provide a sound model for photodesorption in dissipative systems.
Y1  - 2011
U6  - https://doi.org/10.1021/jp205902k
SN  - 1089-5639
VL  - 115
IS  - 39
SP  - 10698
EP  - 10707
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Bouvier, A.
A1  - Bradbury, S. M.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cannon, A.
A1  - Cesarini, A.
A1  - Christiansen, J. L.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dickherber, R.
A1  - Duke, C.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Finley, J. P.
A1  - Finnegan, G.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gibbs, K.
A1  - Gillanders, G. H.
A1  - Godambe, S.
A1  - Griffin, S.
A1  - Grube, J.
A1  - Guenette, R.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Huan, H.
A1  - Hughes, G.
A1  - Hui, C. M.
A1  - Humensky, T. B.
A1  - Imran, A.
A1  - Kaaret, P.
A1  - Karlsson, N.
A1  - Kertzman, M.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Lyutikov, M.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - McCutcheon, M.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nunez, P.
A1  - Ong, R. A.
A1  - Orr, M.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pizlo, F.
A1  - Pohl, Martin
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Roache, E.
A1  - Rose, H. J.
A1  - Ruppel, J.
A1  - Saxon, D. B.
A1  - Schroedter, M.
A1  - Sembroski, G. H.
A1  - Sentuerk, G. D.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Tesic, G.
A1  - Theiling, M.
A1  - Thibadeau, S.
A1  - Tsurusaki, K.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Vivier, M.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Weisgarber, T.
A1  - Williams, D. A.
A1  - Zitzer, B.
T1  - Detection of pulsed Gamma Rays Above 100 GeV from the Crab Pulsar
JF  - Science
N2  - We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.
Y1  - 2011
U6  - https://doi.org/10.1126/science.1208192
SN  - 0036-8075
VL  - 334
IS  - 6052
SP  - 69
EP  - 72
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Sun, Y. -P.
A1  - Hennies, Franz
A1  - Pietzsch, Annette
A1  - Kennedy, B.
A1  - Schmitt, Thorsten
A1  - Strocov, Vladimir N.
A1  - Andersson, Joakim
A1  - Berglund, Martin
A1  - Rubensson, Jan-Erik
A1  - Aidas, K.
A1  - Gel'mukhanov, F.
A1  - Odelius, Michael
A1  - Föhlisch, Alexander
T1  - Intramolecular soft modes and intermolecular interactions in liquid acetone
JF  - Physical review : B, Condensed matter and materials physics
N2  - Resonant inelastic x-ray scattering spectra excited at the O1s(-1)pi* resonance of liquid acetone are presented. Scattering to the electronic ground state shows a resolved vibrational progression where the dominant contribution is due to the C-O stretching mode, thus demonstrating a unique sensitivity of the method to the local potential energy surface in complex molecular systems. For scattering to electronically excited states, soft vibrational modes and, to a smaller extent, intermolecular interactions give a broadening, which blurs the vibrational fine structure. It is predicted that environmental broadening is dominant in aqueous acetone.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevB.84.132202
SN  - 1098-0121
VL  - 84
IS  - 13
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Kiel, Mareike
A1  - Möhwald, Helmuth
A1  - Bargheer, Matias
T1  - Broadband measurements of the transient optical complex dielectric function of a nanoparticle/polymer composite upon ultrafast excitation
JF  - Physical review : B, Condensed matter and materials physics
N2  - We determined experimentally the complex transient optical dielectric function of a well-characterized polyelectrolyte/gold-nanoparticle composite system over a broad spectral range upon short pulse laser excitation by simultaneously measuring the time-dependent reflectance and transmittance of white light pulses with femtosecond pump-probe spectroscopy. We extracted directly the ultrafast changes in the real and imaginary parts of the effective dielectric function, epsilon(eff)(r) (omega,t)and epsilon(eff)(i) (omega,t), from the experiment. This complete experimental set of information on the time-dependent complex dielectric function challenges theories modeling the transient dielectric function of gold particles and the effective medium.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevB.84.165121
SN  - 1098-0121
VL  - 84
IS  - 16
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Berenstein, Igal
A1  - Beta, Carsten
T1  - Flow-induced control of chemical turbulence
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - We report spatiotemporal chaos in the Oregonator model of the Belousov-Zhabotinsky reaction. Spatiotemporal chaos spontaneously develops in a regime, where the underlying local dynamics show stable limit cycle oscillations (diffusion-induced turbulence). We show that spatiotemporal chaos can be suppressed by a unidirectional flow in the system. With increasing flow velocity, we observe a transition scenario from spatiotemporal chaos via a regime of travelling waves to a stationary steady state. At large flow velocities, we recover the known regime of flow distributed oscillations.
KW  - chaos
KW  - chemical equilibrium
KW  - chemically reactive flow
KW  - reaction kinetics theory
KW  - spatiotemporal phenomena
KW  - turbulence
Y1  - 2011
U6  - https://doi.org/10.1063/1.3656248
SN  - 0021-9606
VL  - 135
IS  - 16
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Blakesley, James C.
A1  - Schubert, Marcel
A1  - Steyrleuthner, Robert
A1  - Chen, Zhihua
A1  - Facchetti, Antonio
A1  - Neher, Dieter
T1  - Time-of-flight measurements and vertical transport in a high electron-mobility polymer
JF  - Applied physics letters
N2  - We investigate charge transport in a high-electron mobility polymer, poly(N, N-bis 2-octyldodecyl-naphthalene-1,4,5,8-bis dicarboximide-2,6-diyl-alt-5,5-2,2-bithiophene) [P(NDI2OD-T2), Polyera ActivInk (TM) N2200]. Time-of-flight measurements reveal electron mobilities approaching those measured in field-effect transistors, the highest ever recorded in a conjugated polymer using this technique. The modest temperature dependence and weak dispersion of the transients indicate low energetic disorder in this material. Steady-state electron-only current measurements reveal a barrier to injection of about 300 meV. We propose that this barrier is located within the P(NDI2OD-T2) film and arises from molecular orientation effects.
Y1  - 2011
U6  - https://doi.org/10.1063/1.3657827
SN  - 0003-6951
VL  - 99
IS  - 18
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Huang, Tingwen
A1  - Chen, Guanrong
A1  - Kurths, Jürgen
T1  - Synchronization of chaotic of chaotic systems with time-varying coupöing delays
JF  - Discrete and continuous dynamical systems : a journal bridging mathematics and sciences ; Series B, Mathematical modelling, analysis and computations
N2  - In this paper, we study the complete synchronization of a class of time-varying delayed coupled chaotic systems using feedback control. In terms of Linear Matrix Inequalities, a sufficient condition is obtained through using a Lyapunov-Krasovskii functional and differential equation in equalities. The conditions can be easily verified and implemented. We present two simulation examples to illustrate the effectiveness of the proposed method.
KW  - Synchronization
KW  - Chaotic System
KW  - Time-varying Delay
Y1  - 2011
U6  - https://doi.org/10.3934/dcdsb.2011.16.1071
SN  - 1531-3492
VL  - 16
IS  - 4
SP  - 1071
EP  - 1082
PB  - American Institute of Mathematical Sciences
CY  - Springfield
ER  - 
TY  - JOUR
A1  - Khader, Patrick H.
A1  - Pachur, Thorsten
A1  - Meier, Stefanie
A1  - Bien, Siegfried
A1  - Jost, Kerstin
A1  - Roesler, Frank
T1  - Memory-based decision-making with heuristics evidence for a controlled activation of memory representations
JF  - Journal of cognitive neuroscience
N2  - Many of our daily decisions are memory based, that is, the attribute information about the decision alternatives has to be recalled. Behavioral studies suggest that for such decisions we often use simple strategies (heuristics) that rely on controlled and limited information search. It is assumed that these heuristics simplify decision-making by activating long-term memory representations of only those attributes that are necessary for the decision. However, from behavioral studies alone, it is unclear whether using heuristics is indeed associated with limited memory search. The present study tested this assumption by monitoring the activation of specific long-term-memory representations with fMRI while participants made memory-based decisions using the "take-the-best" heuristic. For different decision trials, different numbers and types of information had to be retrieved and processed. The attributes consisted of visual information known to be represented in different parts of the posterior cortex. We found that the amount of information required for a decision was mirrored by a parametric activation of the dorsolateral PFC. Such a parametric pattern was also observed in all posterior areas, suggesting that activation was not limited to those attributes required for a decision. However, the posterior increases were systematically modulated by the relative importance of the information for making a decision. These findings suggest that memory-based decision-making is mediated by the dorsolateral PFC, which selectively controls posterior storage areas. In addition, the systematic modulations of the posterior activations indicate a selective boosting of activation of decision-relevant attributes.
Y1  - 2011
SN  - 0898-929X
VL  - 23
IS  - 11
SP  - 3540
EP  - 3554
PB  - MIT Press
CY  - Cambridge
ER  -