@article{1758, author = {{Rockstuhl, Carsten and Zentgraf, Thomas and Pshenay-Severin, Ekaterina and Petschulat, Jörg and Chipouline, Arkadi and Kuhl, Jürgen and Pertsch, Thomas and Giessen, Harald and Lederer, Falk}}, issn = {{1094-4087}}, journal = {{Optics Express}}, number = {{14}}, publisher = {{The Optical Society}}, title = {{{The origin of magnetic polarizability in metamaterials at optical frequencies - an electrodynamic approach}}}, doi = {{10.1364/oe.15.008871}}, volume = {{15}}, year = {{2007}}, } @article{1759, author = {{Zentgraf, Thomas and Meyrath, T. P. and Seidel, A. and Kaiser, S. and Giessen, H. and Rockstuhl, C. and Lederer, F.}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{3}}, publisher = {{American Physical Society (APS)}}, title = {{{Babinet’s principle for optical frequency metamaterials and nanoantennas}}}, doi = {{10.1103/physrevb.76.033407}}, volume = {{76}}, year = {{2007}}, } @article{1760, author = {{Guo, Hongcang and Liu, Na and Fu, Liwei and Meyrath, Todd P. and Zentgraf, Thomas and Schweizer, Heinz and Giessen, Harald}}, issn = {{1094-4087}}, journal = {{Optics Express}}, number = {{19}}, publisher = {{The Optical Society}}, title = {{{Resonance hybridization in double split-ring resonator metamaterials}}}, doi = {{10.1364/oe.15.012095}}, volume = {{15}}, year = {{2007}}, } @article{1761, author = {{Rockstuhl, Carsten and Lederer, Falk and Zentgraf, Thomas and Giessen, Harald}}, issn = {{0003-6951}}, journal = {{Applied Physics Letters}}, number = {{15}}, publisher = {{AIP Publishing}}, title = {{{Enhanced transmission of periodic, quasiperiodic, and random nanoaperture arrays}}}, doi = {{10.1063/1.2799240}}, volume = {{91}}, year = {{2007}}, } @article{1762, author = {{Nau, D. and Schönhardt, A. and Christ, A. and Zentgraf, Thomas and Bauer, Ch. and Kuhl, J. and Giessen, H.}}, issn = {{1862-6300}}, journal = {{physica status solidi (a)}}, number = {{11}}, pages = {{3848--3861}}, publisher = {{Wiley-Blackwell}}, title = {{{Optical properties of disordered metallic photonic crystal slabs}}}, doi = {{10.1002/pssa.200776411}}, volume = {{204}}, year = {{2007}}, } @article{1763, author = {{Utikal, Tobias and Zentgraf, Thomas and Kuhl, Jürgen and Giessen, Harald}}, issn = {{1098-0121}}, journal = {{Physical Review B}}, number = {{24}}, publisher = {{American Physical Society (APS)}}, title = {{{Dynamics and dephasing of plasmon polaritons in metallic photonic crystal superlattices: Time- and frequency-resolved nonlinear autocorrelation measurements and simulations}}}, doi = {{10.1103/physrevb.76.245107}}, volume = {{76}}, year = {{2007}}, } @inbook{17846, author = {{Mindt, Ilka}}, booktitle = {{Valency. Theoretical, Descriptive and Cognitive Issues}}, editor = {{Herbst, Thomas and Götz-Votteler, Katrin}}, pages = {{101 -- 115}}, publisher = {{Mouton de Gruyter}}, title = {{{The valency of experiential and evaluative adjectives}}}, year = {{2007}}, } @inproceedings{18928, author = {{Dynia, Miroslaw and Łopuszański, Jakub and Schindelhauer, Christian}}, booktitle = {{Proc. of the 14th Colloquium on Structural Information and Communication Complexity (SIROCCO)}}, isbn = {{9783540729181}}, pages = {{37---- 46}}, title = {{{Why Robots Need Maps}}}, doi = {{10.1007/978-3-540-72951-8_5}}, year = {{2007}}, } @inproceedings{18929, author = {{Dynia, Miroslaw and Korzeniowski, Miroslaw and Kutyłowski, Jarosław}}, booktitle = {{Proc. of the 33rd International Conference on Current Trends in Theory and Practice of Computer Science (SOFSEM'07)}}, isbn = {{9783540695066}}, issn = {{0302-9743}}, pages = {{260----271}}, title = {{{Competitive Maintenance of Minimum Spanning Trees in Dynamic Graphs}}}, doi = {{10.1007/978-3-540-69507-3_21}}, volume = {{4362}}, year = {{2007}}, } @phdthesis{18931, author = {{Kutylowski, Jaroslaw}}, title = {{{Using Mobile Relays for Ensuring Connectivity in Sparse Networks}}}, year = {{2007}}, } @unpublished{18933, author = {{Kutylowski, Jaroslaw}}, title = {{{Competitive Maintenance of Minimum Spanning Trees under Stochastic Adversaries}}}, year = {{2007}}, } @book{19007, author = {{Eke, Norbert Otto}}, pages = {{296}}, publisher = {{Erich Schmidt}}, title = {{{Wort/Spiele. Drama – Film – Literatur}}}, year = {{2007}}, } @book{19080, editor = {{Eke, Norbert Otto and Geulen, Eva}}, pages = {{382}}, publisher = {{Erich Schmidt}}, title = {{{Tiere, Texte, Spuren}}}, year = {{2007}}, } @inbook{19139, author = {{Seng, Eva- Maria}}, booktitle = {{Jülicher Geschichtsblätter Bd. 73}}, title = {{{„Zwischen Utopie und Realität. Die ‚Idealstadt’ Jülich als Ausdruck des frühneuzeitlichen Ordnungsdenkens“}}}, volume = {{Bd. 73}}, year = {{2007}}, } @inbook{19140, author = {{Seng, Eva- Maria}}, booktitle = {{Geschichte der bildenden Kunst in Deutschland, Bd. 4 Spätgotik und Renaissance}}, editor = {{Krause, Katharina}}, pages = {{266f}}, title = {{{Jörg Held (um 1454-1527), Petrarca-Meister, Vogelschau der Stadt Augsburg}}}, year = {{2007}}, } @inbook{19332, author = {{Eke, Norbert Otto}}, booktitle = {{Von Sommerträumen und Wintermärchen. Versepen im Vormärz}}, editor = {{Füllner, Bernd and Füllner, Karin}}, pages = {{49--71}}, publisher = {{Aisthesis}}, title = {{{Grausame Spiegel. Lenaus Blick zurück nach vorn: Die Albigenser. Freie Dichtungen}}}, year = {{2007}}, } @inbook{19333, author = {{Eke, Norbert Otto and Geulen, Eva}}, booktitle = {{Tiere, Texte, Spuren}}, editor = {{Eke, Norbert Otto and Geulen, Eva}}, pages = {{1--3}}, publisher = {{Erich Schmidt}}, title = {{{Tiere, Texte, Spuren (Vorwort)}}}, year = {{2007}}, } @inbook{19335, author = {{Eke, Norbert Otto}}, booktitle = {{Literarischer Antisemitismus nach Auschwitz}}, editor = {{Bogdal, Klaus-Michael and Holz, Klaus and Lorenz, Matthias N.}}, pages = {{243--261}}, publisher = {{Metzler}}, title = {{{Im „deutschen Zauberwald“. Spiegel- und Kippfiguren des Antisemitismus in deutschsprachiger Gegenwartsliteratur}}}, year = {{2007}}, } @inbook{19336, author = {{Eke, Norbert Otto}}, booktitle = {{Was einmal wirklich war. Zum Werk Robert Menasses}}, editor = {{Schörkhuber, Eva}}, pages = {{237--250}}, publisher = {{Sonderzahl}}, title = {{{„Nichts, was einen Anfang hatte, ist unendlich.“ Robert Menasses Arbeit an der Differenz – Die Zerstörung der Welt als Wille und Vorstellung. Frankfurter Poetikvorlesungen}}}, year = {{2007}}, } @inbook{19337, author = {{Eke, Norbert Otto}}, booktitle = {{Walter-Hasenclever-Gesellschaft. Jahrbuch 2005/2006}}, pages = {{113--128}}, publisher = {{Shaker}}, title = {{{Das ‚kleine Sagen’ und das ‚große Sagen’. Herta Müllers Gegenschrift}}}, year = {{2007}}, } @inbook{19338, author = {{Eke, Norbert Otto}}, booktitle = {{Das Unterhaltungsstück um 1800. Literaturhistorische Konfigurationen – Signaturen der Moderne. Zur Geschichte des Theaters als Reflexionsmedium von Gesellschaft, Politik und Ästhetik}}, editor = {{Birgfeld, Johannes and Conter, Claude D.}}, pages = {{3--29}}, publisher = {{Wehrhahn}}, title = {{{Schreckbilder: Die Revolution als Aufstand der ‚schwarzen Männer’}}}, year = {{2007}}, } @inproceedings{2389, author = {{Lietsch, Stefan and Marquardt, Oliver}}, booktitle = {{Proc. Int. Symp. on Visual Computing (ISVC)}}, isbn = {{978-3-540-76857-9}}, pages = {{724--733}}, publisher = {{Springer}}, title = {{{A CUDA-Supported Approach to Remote Rendering}}}, volume = {{4841}}, year = {{2007}}, } @inproceedings{2390, author = {{Voss, Kerstin}}, booktitle = {{Proc. Int. Conf. on Semantics, Knowledge and Grid (SKG)}}, isbn = {{0-7695-3007-9}}, pages = {{50--55}}, publisher = {{IEEE Computer Society}}, title = {{{Comparing Fault Tolerance Mechanisms for Self-Organizing Resource Management in Grids}}}, doi = {{10.1109/SKG.2007.40}}, year = {{2007}}, } @inproceedings{2391, author = {{Battré, Dominic and Djemame, Karim and Kao, Odej and Voss, Kerstin}}, booktitle = {{Proc. Int. Conf. on Security and Privacy in Communications Networks (SecureComm)}}, pages = {{193--198}}, publisher = {{IEEE}}, title = {{{Gaining Users' Trust by Publishing Failure Probabilities}}}, doi = {{10.1109/SECCOM.2007.4550331}}, year = {{2007}}, } @techreport{2394, author = {{Beutel, Jan and Plessl, Christian and Woehrle, Matthias}}, title = {{{Increasing the Reliability of Wireless Sensor Networks with a Unit Testing Framework}}}, year = {{2007}}, } @inproceedings{2396, author = {{Voss, Kerstin and Djemame, Karim and Gourlay, Iain and Padgett, James}}, booktitle = {{Proc. Int. Worksh. on Grid Economics and Business Models (GECON)}}, editor = {{Altmann, Jörn and Veit, Daniel}}, pages = {{170--175}}, publisher = {{Springer}}, title = {{{AssessGrid, Economic Issues Underlying Risk Awareness in Grids}}}, doi = {{10.1007/978-3-540-74430-6_14}}, volume = {{4685}}, year = {{2007}}, } @inproceedings{2397, author = {{Voss, Kerstin}}, booktitle = {{Proc. Int. Conf. on Networking and Services (ICNS)}}, isbn = {{0-7695-2858-9}}, pages = {{27--32}}, publisher = {{IEEE Computer Society}}, title = {{{Enhance Self-managing Grids by Risk Management}}}, doi = {{10.1109/ICNS.2007.61}}, year = {{2007}}, } @inproceedings{2398, author = {{Lietsch, Stefan and Zabel, Henning and Berssenbruegge, Jan}}, booktitle = {{Proc. ASME Computers and Information in Engineering Conference (CIE)}}, isbn = {{0-7918-3806-4}}, publisher = {{ASME}}, title = {{{Computational Steering of Interactive and Distributed Virtual Reality Applications}}}, year = {{2007}}, } @inproceedings{2399, author = {{Birkenheuer, Georg and Majlender, Peter and Nitsche, Holger and Voss, Kerstin and Weber, Elmar}}, booktitle = {{Proc. Cracow Grid Workshop (CGW)}}, title = {{{Gather and Prepare Monitoring Data for Estimating Resource Stability}}}, year = {{2007}}, } @inproceedings{2400, author = {{Berssenbrügge, Jan and Lietsch, Stefan}}, booktitle = {{Proc. Worksh. Augmented & Virtual Reality in der Produktentstehung}}, isbn = {{978-3-939350-28-6}}, pages = {{67--80}}, publisher = {{Heinz Nixdorf Institut}}, title = {{{Verteilte Berechnung und Darstellung automobiler Scheinwerfer}}}, volume = {{209}}, year = {{2007}}, } @inproceedings{20374, author = {{Dorigo, Marco and Hamann, Heiko and Szymanski, Marc and Wörn, Heinz and Shi, Yuhui}}, booktitle = {{IEEE Swarm Intelligence Symposium, Honolulu, USA, April 1-5}}, pages = {{310----315}}, publisher = {{IEEE Press}}, title = {{{Orientation in a Trail Network by Exploiting its Geometry for Swarm Robotics}}}, doi = {{10.1109/SIS.2007.367953}}, year = {{2007}}, } @article{20383, author = {{Jäger, R and Purpura, M and Geiss, KR and Weiß, M and Baumeister, Jochen and Amatulli, F and Schröder, L and Herwegen, H}}, issn = {{1550-2783}}, journal = {{J Int Soc Sports Nutr}}, pages = {{23}}, title = {{{The effect of phosphatidylserine on golf performance.}}}, doi = {{10.1186/1550-2783-4-23}}, volume = {{4}}, year = {{2007}}, } @inproceedings{20431, author = {{Hamann, Heiko and Wörn, Heinz and Sahin, Erol and Spears, Winfield and Winfield, Winfield}}, booktitle = {{Swarm Robotics - Second SAB 2006 International Workshop}}, pages = {{43----55}}, title = {{{An analytical and spatial model of foraging in a swarm of robots}}}, doi = {{10.1007/978-3-540-71541-2_4}}, volume = {{4433}}, year = {{2007}}, } @inproceedings{20432, abstract = {{Designing and implementing artificial self-organizing systems is a challenging task since they typically behave non- intuitive and only little theoretical foundations exist. Predicting a system of many components with a huge amount of interactions is beyond human skills. The currently common use of simulations for design support is not satisfying, as it is time-consuming and the results are most likely sub- optimal. In this work, we present the derivation of an analytical, time-, and space-continuous model for a swarm of autonomous robots based on the Fokker-Planck equation. While the motion model is in most parts physically motivated, the communication model is based on a heuristic approach. A showcase application to a recently proposed scenario of collective perception in a huge swarm of robots with very limited abilities is given and the simulation results are compared to the model. Despite the high level of abstraction, the prediction discrepancies are small and the parameters can be mapped one-to-one from the model to the control algorithm. Finally, we give an outlook on the capabilities of the proposed model, discuss its limitations, and suggest an improvement that could reduce the number of empirically determined parameters.}}, author = {{Hamann, Heiko and Wörn, Heinz}}, booktitle = {{First International Conference on Self-Adaptive and Self-Organizing Systems (SASO 2007)}}, isbn = {{0769529062}}, pages = {{23----31}}, title = {{{A Space- and Time-Continuous Model of Self-Organizing Robot Swarms for Design Support}}}, doi = {{10.1109/saso.2007.3}}, year = {{2007}}, } @article{20433, author = {{Hamann, Heiko and Wörn, Heinz and Nagy, Marius and Nagy, Naya}}, journal = {{Parallel Processing Letters}}, number = {{3}}, pages = {{287----298}}, title = {{{Embodied Computation}}}, volume = {{17}}, year = {{2007}}, } @inproceedings{20434, abstract = {{Current research in Micro, Nano and Swarm Robots as results of the European projects Miniman, MiCRoN and I-SWARM will be presented. First, the design and the control of 5 to 10cm3 sized mobile micro robots with five degrees of freedom will be shown. They can handle miniaturized parts as for example an optical component or a biological cell with a size in the micrometre-area with an accuracy of 100nm under a microscope or a raster-electron microscope. Second, the design and the control of a 1cm3-sized mobile untethered micro robot will be demonstrated. Here, the robot consists of five parts: the Piezzo locomotion module, the micro control unit, the communication unit, the navigation system and the micro gripper. The mobile robot can be guided and positioned in an arena with an accuracy of 5 micrometre and can be programmed and controlled over the wireless communication unit. Third, the design and the control of 3 × 3 × 3 mm3 sized micro-/nanorobots with 2 degrees of freedom will be presented. The transmission of energy and the communication between the robots is realized via infrared. The robot controller is fully integrated and has limited functionalities. Via basic sensors communication functions and elementary rules and behaviours the micro robot can act in a swarm consisting of hundreds and thousands of robots. Future applications could be monitoring-, inspection-, exploring-tasks etc. of big areas or objects.}}, author = {{Hamann, Heiko and Szymanski, Marc and Wörn, Heinz and Estana, Ramon and Xie, Ming and Dubowsky, Steven}}, booktitle = {{Advances in Climbing and walking robots. Proceedings of 10th International Conference (CLAWAR'07), Singapore, July 16-18}}, pages = {{15----24}}, title = {{{From Micro to Nano and Swarm Robotics}}}, doi = {{10.1142/9789812770189_0003}}, year = {{2007}}, } @article{17980, author = {{Ziegler, Martin}}, issn = {{1571-0661}}, journal = {{Electronic Notes in Theoretical Computer Science}}, pages = {{255--274}}, title = {{{Revising Type-2 Computation and Degrees of Discontinuity}}}, doi = {{10.1016/j.entcs.2006.08.015}}, year = {{2007}}, } @article{17981, author = {{Ziegler, Martin}}, issn = {{1432-4350}}, journal = {{Theory of Computing Systems}}, pages = {{177--206}}, title = {{{Real Hypercomputation and Continuity}}}, doi = {{10.1007/s00224-006-1343-6}}, year = {{2007}}, } @inbook{17982, author = {{Ziegler, Martin}}, booktitle = {{Lecture Notes in Computer Science}}, isbn = {{9783540730002}}, issn = {{0302-9743}}, title = {{{(Short) Survey of Real Hypercomputation}}}, doi = {{10.1007/978-3-540-73001-9_86}}, year = {{2007}}, } @inbook{17983, author = {{Meer, Klaus and Ziegler, Martin}}, booktitle = {{Mathematical Foundations of Computer Science 2007}}, isbn = {{9783540744559}}, issn = {{0302-9743}}, title = {{{Real Computational Universality: The Word Problem for a Class of Groups with Infinite Presentation}}}, doi = {{10.1007/978-3-540-74456-6_64}}, year = {{2007}}, } @unpublished{17984, abstract = {{The unit cost model is both convenient and largely realistic for describing integer decision algorithms over (+,*). Additional operations like division with remainder or bitwise conjunction, although equally supported by computing hardware, may lead to a considerable drop in complexity. We show a variety of concrete problems to benefit from such NON-arithmetic primitives by presenting and analyzing corresponding fast algorithms.}}, author = {{Lürwer-Brüggemeier, Katharina and Ziegler, Martin}}, booktitle = {{arXiv:0709.0624}}, title = {{{On Faster Integer Calculations using Non-Arithmetic Primitives}}}, year = {{2007}}, } @techreport{18285, author = {{Ziegler, Martin}}, title = {{{Real Computability and Hypercomputation}}}, year = {{2007}}, } @inproceedings{18347, abstract = {{The validation of material flow models as well as the selection of promising strategies for the generation of a successful experiment plan is a time-consuming process. A new approach is presented, which supports the simulation expert in his working process by giving him the opportunity to modify the simulated simulation run and afterwards compare the effects of his modification with the original setting, online and in one user interface, implemented by switching the visualizations between the simulation runs or opening up to 5 parallel 3D windows. The method developed therefore clones existing simulation runs online and allows the navigation within these existing simulation runs. The method has been implemented and is validated by a test model, which describes in detail the new working process of a modeler. New research questions are derived from this work, which will define following working steps. }}, author = {{Fischer, Matthias and Laroque, Christoph and Huber, Daniel and Krokowski, Jens and Mueck, Bengt and Kortenjan, Michael and Aufenanger, Mark and Dangelmaier, Wilhelm}}, booktitle = {{European Simulation and Modelling Conference (ESM 2007)}}, pages = {{499----505}}, title = {{{Interactive Refinement of a Material Flow Simulation Model by Comparing Multiple Simulation Runs in one 3D Environment}}}, year = {{2007}}, } @inproceedings{18349, author = {{Dangelmaier, Wilhelm and Laroque, Christoph and Fischer, Matthias}}, booktitle = {{Augmented & Virtual Reality in der Produktentstehung}}, pages = {{95--110}}, publisher = {{Verlagsschriftenreihe des Heinz Nixdorf Instituts, Paderborn}}, title = {{{Ein ganzheitlicher Ansatz zur immersiven 3D-Materialflusssimulation innerhalb der Digitalen Fabrik}}}, volume = {{209}}, year = {{2007}}, } @inproceedings{1840, author = {{Woldegebreal, Dereje H. and Karl, Holger}}, booktitle = {{2007 4th International Symposium on Wireless Communication Systems}}, isbn = {{9781424409785}}, publisher = {{IEEE}}, title = {{{Multiple-Access Relay Channel with Network Coding and Non-Ideal Source-Relay Channels}}}, doi = {{10.1109/iswcs.2007.4392437}}, year = {{2007}}, } @inproceedings{1842, author = {{Karl, Holger}}, publisher = {{Communication in Distributed Systems (KiVS), 2007 ITG-GI Conference}}, title = {{{Optimizing sleeping intervals in preamble sampling MAC for WSNs}}}, year = {{2007}}, } @inproceedings{18572, abstract = {{We present random sampling algorithms that with probability at least 1 − δ compute a (1 ±ε)-approximation of the clustering coefficient and of the number of bipartite clique subgraphs of a graph given as an incidence stream of edges. The space used by our algorithm to estimate the clustering coefficient is inversely related to the clustering coefficient of the network itself. The space used by our algorithm to compute the number K 3,3 of bipartite cliques is proportional to the ratio between the number of K 1,3 and K 3,3 in the graph. Since the space complexity depends only on the structure of the input graph and not on the number of nodes, our algorithms scale very well with increasing graph size. Therefore they provide a basic tool to analyze the structure of dense clusters in large graphs and have many applications in the discovery of web communities, the analysis of the structure of large social networks and the probing of frequent patterns in large graphs. We implemented both algorithms and evaluated their performance on networks from different application domains and of different size; The largest instance is a webgraph consisting of more than 135 million nodes and 1 billion edges. Both algorithms compute accurate results in reasonable time on the tested instances.}}, author = {{Buriol, Luciana S. and Frahling, Gereon and Leonardi, Stefano and Sohler, Christian}}, booktitle = {{Proceedings of the 15th European Symposium on Algorithms (ESA)}}, isbn = {{9783540755197}}, pages = {{618--632}}, publisher = {{Springer}}, title = {{{Estimating Clustering Indexes in Data Streams}}}, doi = {{10.1007/978-3-540-75520-3_55}}, volume = {{4698}}, year = {{2007}}, } @inbook{18588, author = {{Schindlmayr, Arno}}, booktitle = {{Probing the Nanoworld }}, editor = {{Urban, Knut and Schneider, Claus Michael and Brückel, Thomas and Blügel, Stefan}}, isbn = {{978-3-89336-462-6}}, issn = {{1433-5506}}, location = {{Jülich}}, pages = {{A1.21--A1.36}}, publisher = {{Forschungszentrum Jülich}}, title = {{{Interaction of radiation with matter. Part II: Light and electrons}}}, volume = {{34}}, year = {{2007}}, } @article{18589, abstract = {{For the calculation of neutral excitations, time-dependent density functional theory (TDDFT) is an exact reformulation of the many-body time-dependent Schrödinger equation, based on knowledge of the density instead of the many-body wavefunction. The density can be determined in an efficient scheme by solving one-particle non-interacting Schrödinger equations—the Kohn–Sham equations. The complication of the problem is hidden in the—unknown—time-dependent exchange and correlation potential that appears in the Kohn–Sham equations and for which it is essential to find good approximations. Many approximations have been suggested and tested for finite systems, where even the very simple adiabatic local-density approximation (ALDA) has often proved to be successful. In the case of solids, ALDA fails to reproduce optical absorption spectra, which are instead well described by solving the Bethe–Salpeter equation of many-body perturbation theory (MBPT). On the other hand, ALDA can lead to excellent results for loss functions (at vanishing and finite momentum transfer). In view of this and thanks to recent successful developments of improved linear-response kernels derived from MBPT, TDDFT is today considered a promising alternative to MBPT for the calculation of electronic spectra, even for solids. After reviewing the fundamentals of TDDFT within linear response, we discuss different approaches and a variety of applications to extended systems.}}, author = {{Botti, Silvana and Schindlmayr, Arno and Del Sole, Rodolfo and Reining, Lucia}}, issn = {{1361-6633}}, journal = {{Reports on Progress in Physics}}, number = {{3}}, pages = {{357--407}}, publisher = {{IOP Publishing}}, title = {{{Time-dependent density-functional theory for extended systems}}}, doi = {{10.1088/0034-4885/70/3/r02}}, volume = {{70}}, year = {{2007}}, } @article{18591, abstract = {{Using density-functional theory, we investigate the stability of the half-metallic ground state of magnetite under different strain conditions. The effects of volume relaxation and internal degrees of freedom are fully taken into account. For hydrostatic compression, planar strain in the (001) plane and uniaxial strain along the [001] direction, we derive quantitative limits beyond which magnetite becomes metallic. As a major new result, we identify the bond length between the octahedrally coordinated iron atoms and their neighbouring oxygen atoms as the main characteristic parameter, and we show that the transition occurs if external strain reduces this interatomic distance from 2.06 Å in equilibrium to below a critical value of 1.99 Å. Based on this criterion, we also argue that planar strain due to epitaxial growth does not lead to a metallic state for magnetite films grown on (111)-oriented substrates.}}, author = {{Friák, Martin and Schindlmayr, Arno and Scheffler, Matthias}}, issn = {{1361-6633}}, journal = {{New Journal of Physics}}, number = {{1}}, publisher = {{IOP Publishing and Deutsche Physikalische Gesellschaft}}, title = {{{Ab initio study of the half-metal to metal transition in strained magnetite}}}, doi = {{10.1088/1367-2630/9/1/005}}, volume = {{9}}, year = {{2007}}, }