115 research outputs found

    Conventional type-II superconductivity in locally non-centrosymmetric LaRh2_2As2_2 single crystals

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    We report on the observation of superconductivity in LaRh2_2As2_2, which is the analogue without ff-electrons of the heavy-fermion system with two superconducting phases CeRh2_2As2_2. A zero-resistivity transition, a specific-heat jump and a drop in magnetic ac susceptibility consistently point to a superconducting transition at a transition temperature of Tc=0.28T_c = 0.28\,K. The magnetic field-temperature superconducting phase diagrams determined from field-dependent ac-susceptibility measurements reveal small upper critical fields μ0Hc212\mu_{\mathrm{0}}H_{c2} \approx 12\,mT for HabH\parallel ab and μ0Hc29\mu_{\mathrm{0}}H_{c2} \approx 9\,mT for HcH\parallel c. The observed Hc2H_{c2} is larger than the estimated thermodynamic critical field HcH_c derived from the heat-capacity data, suggesting that LaRh2_2As2s_2 is a type-II superconductor with Ginzburg-Landau parameters κGLab1.9\kappa^{ab}_{GL} \approx 1.9 and κGLc2.7\kappa^{c}_{GL}\approx 2.7. The microscopic Eliashberg theory indicates superconductivity to be in the weak-coupling regime with an electron-phonon coupling constant λeph0.4\lambda_{e-ph} \approx 0.4. Despite a similar TcT_c and the same crystal structure as the Ce compound, LaRh2_2As2_2 displays conventional superconductivity, corroborating the substantial role of the 4ff electrons for the extraordinary superconducting state in CeRh2_2As2_2.Comment: 11 pages, 8 figure

    Capacitively Coupled Silicon-Organic Hybrid Modulator for 200 Gbit/s PAM-4 Signaling

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    We demonstrate capacitively coupled silicon-organic hybrid (SOH) modulator with a π-voltage-length product of 1.3 V mm and 3 dB EO bandwidth exceeding 65 GHz. The modulator is used for 200 Gbit/s (100 GBd) PAM-4 signaling

    Nanophotonic modulators and photodetectors using silicon photonic and plasmonic device concepts

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    Nanophotonic modulators and photodetectors are key building blocks for high-speed optical interconnects in datacom and telecom networks. Besides power efficiency and high electro-optic bandwidth, ultra-compact footprint and scalable co-integration with electronic circuitry are indispensable for highly scalable communication systems. In this paper, we give an overview on our recent progress in exploring nanophotonic modulators and photodetectors that combine the specific strengths of silicon photonic and plasmonic device concepts with hybrid integration approaches. Our work comprises electro-optic modulators that exploit silicon-organic hybrid (SOH) and plasmonic-organic hybrid (POH) integration to enable unprecedented energy efficiency and transmission speed, as well as waveguide-based plasmonic internal photo-emission detectors (PIPED) with record-high sensitivities and bandwidths

    Photonic-Electronic Ultra-Broadband Signal Processing: Concepts, Devices, and Applications

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    Combining photonic integrated circuits (PIC) with millimeter-wave electronics opens novel perspectives in generation and detection of ultra-broadband signals with disruptive potential for a wide variety of applications. Here, we will give an overview on our recent progress in the field of ultra-broadband photonic-electronic signal processing, covering device concepts such as silicon plasmonic integration, signal processing concepts such as Kramers-Kronig-based phase reconstruction of THz signals, as well as application demonstrations in the field of high-speed wireless data transmission

    Annex 2 - Metrics and methodology

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    This annex on methods and metrics provides background information on material used in the Working Group III Contribution to the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (WGIII AR5). The material presented in this annex documents metrics, methods, and common data sets that are typically used across multiple chapters of the report. The annex is composed of three parts: Part I introduces standards metrics and common definitions adopted in the report; Part II presents methods to derive or calculate certain quantities used in the report; and Part III provides more detailed background information about common data sources that go beyond what can be included in the chapters. While this structure may help readers to navigate through the annex, it is not possible in all cases to unambiguously assign a certain topic to one of these parts, naturally leading to some overlap between the parts

    100 Gbit/s serial transmission using a silicon-organic hybrid (SOH) modulator and a duobinary driver IC

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    100 Gbit/s three-level (50 Gbit/s 00K) signals are generated using a silicon-organic hybrid modulator and a BiCMOS duobinary driver IC at a BER of 8.5x10(-5)(<10(-12)). We demonstrate dispersion-compensated transmission over 5 km

    100 Gbit/s serial transmission using a silicon-organic hybrid (SOH) modulator and a duobinary driver IC

    Get PDF
    100 Gbit/s three-level (50 Gbit/s 00K) signals are generated using a silicon-organic hybrid modulator and a BiCMOS duobinary driver IC at a BER of 8.5x10(-5)(<10(-12)). We demonstrate dispersion-compensated transmission over 5 km

    Acting while perceiving: assimilation precedes contrast

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    To explore the nature of specific interactions between concurrent perception and action, participants were asked to move one of their hands in a certain direction while simultaneously observing an independent stimulus motion of a (dis)similar direction. The kinematics of the hand trajectories revealed a form of contrast effect (CE) in that the produced directions were biased away from the perceived directions (“Experiment 1”). Specifically, the endpoints of horizontal movements were lower when having watched an upward as opposed to a downward motion. However, when participants moved under higher speed constraints and were not presented with the stimulus motion prior to initiating their movements, the CE was preceded by an assimilation effect, i.e., movements were biased toward the stimulus motion directions (“Experiment 2”). These findings extend those of related studies by showing that CEs of this type actually correspond to the second phase of a bi-phasic pattern of specific perception–action interference
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