Recent Additions

  • Publication
    Limitations of nearest-neighbor quantum networks
    ( 2022)
    Hahn, F.
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    Dahlberg, A.
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    Pappa, Anna
    Quantum communication research has in recent years shifted to include multipartite networks for which questions of quantum network routing naturally emerge. To understand the potential for multipartite routing, we focus on the most promising architectures for future quantum networks-those connecting nodes close to each other. Nearest-neighbor networks, such as rings, lines, and grids, have been studied under different communication scenarios to facilitate the sharing of quantum resources especially in the presence of bottlenecks. We analyze the potential of nearest-neighbor entangling gate quantum networks and identify some serious limitations by demonstrating that rings and lines cannot overcome common bottleneck communication problems.
  • Publication
    Electrocaloric temperature changes in epitaxial Ba1-xSrxTiO3 films
    ( 2022)
    Magalhaes, Bruno
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    Engelhardt, Stefan
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    ; ;
    Nielsch, Kornelius
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    Hühne, Ruben
    The basic aim of our study is to investigate the correlation between structural parameters and the electrocaloric effect in lead-free epitaxial Ba1-xTiO3 (BSTO) based thin film architectures. Therefore, BSTO thin films with Sr contents of x = 0 to x = 0.3 were grown on SrRuO3 buffered SrTiO3 single crystalline substrates by pulsed laser deposition. Structural characterization verified an epitaxial growth for all Sr contents with an additional tetragonal distortion compared to bulk material. Temperature and frequency-dependent measurements of dielectric properties revealed increased permittivity values for thicker films with broad maxima indicating a diffuse phase transition. The temperature of maximum permittivity decreases with increasing Sr content, whereas polarization measurements indicate a relaxor-like behaviour in particular above room temperature. Adiabatic temperature changes were determined with the indirect method resulting in |ΔT| values of up to 2.9 K for a 680 nm thick BSTO layer with x = 0.3 at an applied electric field of 750 kV cm-1.
  • Publication
    Automatic Analog Design and Layout Generation: Chances and Hurdles
    ( 2022-10-11)
    To this day, analog circuits elude comprehensive layout synthesis and therefore still have to be designed manually. Due to shrinking to ever more advance nodes as well as due to increasing design complexity, the pressure on analog designers is immense and growing. Despite a variety of improvements in design environments, full analog automation is still in its infancy. One promising approach – besides synthesis methods - applies procedural methods and specifically generators in the design process. Generators create design data automatically in an often (but not always) PCell-like way. Novel cross-technology concepts allow generators to be technologies-agnostic, too. Thus, they not only systematize the design process and shorten design time, generators also open up the possibility of analog design reuse across design projects. Especially when requirements and/or target technologies change, design efficiency can be significantly increased. However, generators are not “for free”. They become effective when applied to the right sweet spot. For example, the initial development efforts will pay off when applied on a broader project view that considers, e.g., a product family or when applied to repetitive or human-unfriendly tasks. This requires both some degree of re-thinking the design approach as well as close cooperation between analog designers and EDA developers. The keynote will first briefly introduce design problems of analog integrated circuits and present current approaches to solve them. This is followed by a closer look at design automation concepts, especially generators that enable the development of cross-technology layout generators. Afterwards, the talk discusses chances and hurdles when applying the generator-based approach in real design projects. An outlook on possible further steps towards a re-use-oriented and highly automated analog design flow concludes the talk.
  • Publication
    Quantum Hologram Distillation
    ( 2022)
    Fuenzalida, Jorge
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    Töpfer, Sebastian
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    Torres, Juan Pérez
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    A recent holography technique based on induced coherence has been introduced. The technique uses photon pairs wherein one of them illuminates the object, and its partner is detected. The photon illuminating the object is never detected. Here we present a novel technique to distill a hologram with undetected photons.
  • Publication
    One-way clock synchronization with single photons
    ( 2022)
    Spiess, Christopher
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    Töpfer, Sebastian
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    Rieländer, Daniel
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    Quantum communication systems can be synchronized using data patterns, precise oscillators, or pulsed lasers. We demonstrate an alternative approach that uses time-bin quanta as a reference for synchronizing low-cost oscillators down to timing uncertainties < 16 ps.

Most viewed

  • Publication
    Tongue pressure and oral conditions affect volatile release from liquid systems in a model mouth
    ( 2012)
    Benjamin, O.
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    Silcock, P.
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    Buettner, Andrea
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    Everett, D.W.
    The release of volatile organic compounds (VOCs) into the mouth cavity is an integral part of the way flavor is perceived. An in vitro model mouth with an artificial tongue was developed to measure the dynamic release of VOCs from liquid model systems [e.g., aqueous solution, oil, and oil-in-water (O/W) emulsions] under oral conditions. The release of seven selected VOCs was affected by the different polarity and vapor pressure of the compounds and their affinity to the liquid system media. Different tongue pressure patterns were applied to the liquid systems, and the release of VOCs was monitored in real time using proton transfer reaction-mass spectrometry. The release was significantly more intense for longer tongue pressure duration and was influenced by the tongue altering the sample surface area and the distribution of the VOCs. The role of saliva (artificial versus human) and the sample temperature had a significant effect on VOC release. Saliva containing mucin and a higher sample temperature enhanced the release.
  • Publication
    Atmosphärendruckplasmen für die Restaurierung?
    ( 2015)
    Thomas, M.
    Plasmas are thermally or electrically charged gas mixtures of electrons, ions and atoms also called "fourth aggregate state", differentiating between "hot" plasmas, e.g. lightning in which all the particles have a high temperature, and "cold" plasmas, which predominantly find use in technical applications and permit treating temperature-sensitive surfaces. Whether in manufacturing mobile phone or printing plastics, these so-called unbalanced plasmas have become indispensable. But are they also relevant for restoration?
  • Publication
    Intelligente Roboter in der Zerlegung
    ( 1997)
    Lay, N.
    Was in der metallverarbeitenden Industrie für den Einsatz von Robotern nicht unbedingt erforderlich ist, muß in der Fleischbranche als grundlegende Voraussetzung gesehen werden: Die Interaktion des Industrieroboters mit seinem Produkt.
  • Publication
    LightProbe: A fully-digital 64-channel ultrasound probe with high-bandwidth optical interface
    ( 2017)
    Hager, P.A.
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    ; ;
    Benini, L.
    A typical medical ultrasound-imaging system consists of a passive probe and a backend system containing the analog frontend and the digital processing unit, to which the probe connects over a coaxial cable harness. Digital processing is increasingly performed in software on powerful GPUs or multicore CPUs. These new system architectures have not only enabled new imaging modalities (Ultrafast Imaging, Vector Flow Estimation), but also reduced system cost, as ultrasound specific hardware is only used for the acquisition of the raw signals. The next step in this evolution are fully-digital ultrasound probes, which integrate the analog frontend and are equipped with a standard digital interface. This allows connecting the probe directly to a standard device, such as a workstation, tablet or mobile phone running an ultrasound software application. So far, this concept has been demonstrated for mobile applications, but is currently limited to a small number of frontend channe ls (â¼16) due to the large digital bandwidth (>10 Gb/s) at the interface between the probe and the mobile device.
  • Publication
    Computer simulation of DIE compaction: Studies and guidelines from the European Dienet Project
    ( 2005)
    Coube, O.
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    Jonsén, P.
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    Kraft, T.
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    Chen, Y.
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    Imbault, D.
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    Doremus, P.
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    Gethin, D.
    The paper describes a simulation of the compaction of a two level part manufactured from a ferrous powder that was completed as a benchmark within the Dienet Thematic Network. The simulations confirm that finite element mesh density has only a very small effect on the predicted density distribution and a small impact on predicted punch force levels. When different codes are compared, they exhibit very close agreement, confirming the suitability of a number of different simulating systems