TY - JOUR A1 - Zoller, Peter A1 - Beth, Thomas A1 - Binosi, D. A1 - Blatt, Rainer A1 - Briegel, Hans J. A1 - Bruss, D. A1 - Calarco, Tommaso A1 - Cirac, Juan Ignacio A1 - Deutsch, David A1 - Eisert, Jens A1 - Ekert, Artur A1 - Fabre, Claude A1 - Gisin, Nicolas A1 - Grangiere, P. A1 - Grassl, Markus A1 - Haroche, Serge A1 - Imamoglu, Atac A1 - Karlson, A. A1 - Kempe, Julia A1 - Kouwenhoven, Leo P. A1 - Kröll, S. A1 - Leuchs, Gerd A1 - Lewenstein, Maciej A1 - Loss, Daniel A1 - Lütkenhaus, Norbert A1 - Massar, Serge A1 - Mooij, J. E. A1 - Plenio, Martin Bodo A1 - Polzik, Eugene A1 - Popescu, Sandu A1 - Rempe, Gerhard A1 - Sergienko, Alexander A1 - Suter, David A1 - Twamley, John A1 - Wendin, Göran A1 - Werner, Reinhard F. A1 - Winter, Andreas A1 - Wrachtrup, Jörg A1 - Zeilinger, Anton T1 - Quantum information processing and communication : Strategic report on current status, visions and goals for research in Europe N2 - We present an excerpt of the document "Quantum Information Processing and Communication: Strategic report on current status, visions and goals for research in Europe", which has been recently published in electronic form at the website of FET (the Future and Emerging Technologies Unit of the Directorate General Information Society of the European Commission, http://www.cordis.lu/ist/fet/qipc-sr.htm). This document has been elaborated, following a former suggestion by FET, by a committee of QIPC scientists to provide input towards the European Commission for the preparation of the Seventh Framework Program. Besides being a document addressed to policy makers and funding agencies (both at the European and national level), the document contains a detailed scientific assessment of the state-of-the-art, main research goals, challenges, strengths, weaknesses, visions and perspectives of all the most relevant QIPC sub-fields, that we report here Y1 - 2005 SN - 1434-6060 ER - TY - THES A1 - Kurcz, Andreas T1 - Qed in periodischen und absorbierenden Medien Y1 - 2005 CY - Potsdam ER - TY - JOUR A1 - Mak, Chris S. K. A1 - Hayer, Anna A1 - Pascu, S. I. A1 - Watkins, Scott E. A1 - Holmes, Andrew B. A1 - Köhler, Anna A1 - Friend, Richard H. T1 - Blue-to-green electrophosphorescence of iridium-based cyclometallated materials. Y1 - 2005 UR - http://www.rsc.org/ej/CC/2005/b508695g.pdf U6 - https://doi.org/10.1039/b508695gb70 SN - 0022-4936 ER - TY - JOUR A1 - Zhu, M. Q. A1 - Armbruster, Dieter A1 - Katzorke, Ines T1 - Does synchronization of networks of chaotic maps lead to control? N2 - We consider networks of chaotic maps with different network topologies. In each case, they are coupled in such a way as to generate synchronized chaotic solutions. By using the methods of control of chaos we are controlling a single map into a predetermined trajectory. We analyze the reaction of the network to such a control. Specifically we show that a line of one-dimensional logistic maps that are unidirectionally coupled can be controlled from the first oscillator whereas a ring of diffusively coupled maps cannot be controlled for more than 5 maps. We show that rings with more elements can be controlled if every third map is controlled. The dependence of unidirectionally coupled maps on noise is studied. The noise level leads to a finite synchronization lengths for which maps can be controlled by a single location. A two-dimensional lattice is also studied. (C) 2005 American Institute of Physics Y1 - 2005 SN - 1054-1500 ER - TY - JOUR A1 - Zillmer, Rüdiger A1 - Pikovskij, Arkadij T1 - Continuous approach for the random-field Ising chain N2 - We study the random-field Ising chain in the limit of strong exchange coupling. In order to calculate the free energy we apply a continuous Langevin-type approach. This continuous model can be solved exactly, whereupon we are able to locate the crossover between an exponential and a power-law decay of the free energy with increasing coupling strength. In terms of magnetization, this crossover restricts the validity of the linear scaling. The known analytical results for the free energy are recovered in the corresponding limits. The outcomes of numerical computations for the free energy are presented, which confirm the results of the continuous approach. We also discuss the validity of the replica method which we then utilize to investigate the sample-to-sample fluctuations of the finite size free energy Y1 - 2005 ER - TY - JOUR A1 - Zhang, B. A1 - Henkel, Carsten A1 - Haller, E. A1 - Wildermuth, S. A1 - Hofferberth, S. A1 - Kruger, P. A1 - Schmiedmayer, Jörg T1 - Relevance of sub-surface chip layers for the lifetime of magnetically trapped atoms N2 - We investigate the lifetime of magnetically trapped atoms above a planar, layered atom chip structure. Numerical calculations of the thermal magnetic noise spectrum are performed, based on the exact magnetic Green function and multi layer reflection coefficients. We have performed lifetime measurements where the center of a side guide trap is laterally shifted with respect to the current carrying wire using additional bias fields. Comparing the experiment to theory, we find a fair agreement and demonstrate that for a chip whose topmost layer is metallic, the magnetic noise depends essentially on the thickness of that layer, as long as the layers below have a, much smaller conductivity; essentially the same magnetic noise would be obtained with a metallic membrane suspended in vacuum. Based on our theory we give general scaling laws of how to reduce the effect of surface magnetic noise on the trapped atoms Y1 - 2005 ER - TY - JOUR A1 - Zen, Achmad A1 - Saphiannikova, Marina A1 - Neher, Dieter A1 - Asawapirom, Udom A1 - Scherf, Ullrich T1 - Comparative study of the field-effect mobility of a copolymer and a binary blend based on poly(3- alkylthiophene)s N2 - The performance of highly soluble regioregular poly[ (3-hexylthiophene)-co-(3-octylthiophetie)] (P3HTOT) as a semiconducting material in organic field-effect transistors (OFETs) is presented in comparison to that of the corresponding homopolymers. Transistors made from as-prepared layers of P3HTOT exhibit a mobility of ca. 7 x 10(-3) cm(2) V-1 s(-1), which is comparable to the performance of transistors made from as-prepared poly(3-hexylthiophene) (P3HT) and almost 6 times larger than the mobility of transistors prepared with poly(3-octylthiophene) (P3OT). On the other hand, the solubility parameter delta(p) of P3HTOT is close to that of the highly soluble P3OT. Moreover, compared to a physical blend of poly(3-hexylthiophene) and poly(3-octylthiophene), the mobility of P3HTOT devices is almost twice as large and the performance does not degrade upon annealing at elevated temperatures. Therefore, the copolymer approach outlined here may be one promising step toward an optimum balance between a Sufficient processability of the polymers from common organic solvents, a high solid state order, and applicable OFET performances Y1 - 2005 SN - 0897-4756 ER - TY - JOUR A1 - Zoller, Gert A1 - Hainzl, Sebastian A1 - Holschneider, Matthias A1 - Ben-Zion, Yehuda T1 - Aftershocks resulting from creeping sections in a heterogeneous fault N2 - We show that realistic aftershock sequences with space-time characteristics compatible with observations are generated by a model consisting of brittle fault segments separated by creeping zones. The dynamics of the brittle regions is governed by static/kinetic friction, 3D elastic stress transfer and small creep deformation. The creeping parts are characterized by high ongoing creep velocities. These regions store stress during earthquake failures and then release it in the interseismic periods. The resulting postseismic deformation leads to aftershock sequences following the modified Omori law. The ratio of creep coefficients in the brittle and creeping sections determines the duration of the postseismic transients and the exponent p of the modified Omori law Y1 - 2005 SN - 0094-8276 ER - TY - JOUR A1 - Zhou, Changsong A1 - Kurths, Jürgen T1 - Noise-sustained and controlled synchronization of stirred excitable media by external forcing N2 - Most of the previous studies on constructive effects of noise in spatially extended systems have focused on static media, e.g., of the reaction diffusion type. Because many active chemical or biological processes occur in a fluid environment with mixing, we investigate here the interplay among noise, excitability, mixing and external forcing in excitable media advected by a chaotic flow, in a two-dimensional FitzHugh-Nagumo model described by a set of reaction- advection-diffusion equations. In the absence of external forcing, noise may generate sustained coherent oscillations of the media in a range of noise intensities and stirring rates. We find that these noise-sustained oscillations can be synchronized by external periodic signals much smaller than the threshold. Analysis of the locking regions in the parameter space of the signal period, stirring rate and noise intensity reveals that the mechanism underlying the synchronization behaviour is a matching between the time scales of the forcing signal and the noise-sustained oscillations. The results demonstrate that, in the presence of a suitable level of noise, the stirred excitable media act as self-sustained oscillatory systems and become much easier to be entrained by weak external forcing. Our results may be verified in experiments and are useful to understand the synchronization of population dynamics of oceanic ecological systems by annual cycles Y1 - 2005 SN - 1367-2630 ER - TY - JOUR A1 - Zen, Achmad A1 - Neher, Dieter A1 - Silmy, Kamel A1 - Hollander, A. A1 - Asawapirom, Udom A1 - Scherf, Ullrich T1 - Improving the performance of organic field effect transistor by optimizing the gate insulator surface N2 - The effect of oxygen plasma treatment and/or silanization with hexamethyldisilazane (HMDS) on the surface chemistry and the morphology of the SiO2-gate insulator were studied with respect to the performance of organic field effect transistors. Using X-ray photoelectron spectroscopy (XPS), it is shown that silanization leads to the growth of a polysiloxane interfacial layer and that longer silanization times increase the thickness of this layer. Most important, silanization reduces the signal from surface contaminations such as oxidized hydrocarbon molecules. In fact, the lowest concentration of these contaminations was found after a combined oxygen plasma/silanization treatment. The results of these investigations were correlated with the characteristic device parameters of polymer field effect transistors with poly(3-hexylthiophene)s as the semiconducting layer. We found that the field effect mobility correlates with the concentration of contaminations as measured by XPS. We, finally, demonstrate that silanization significantly improves the operational stability of the device in air compared to the untreated devices Y1 - 2005 ER -