17 research outputs found

    Analysis of the C2 system effectiveness using continous processing time

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    A typical command-control (C[superscript]2) system was modeled and analyzed for peace-time and war-time as Conflict-free Stochastic Timed Placed Petri Net. The decomposition of the model provides an easier method to formulate and to simulate system states. The procedures to evaluate time-related measures: system maximum throughput rate, measured by minimum average circuit processing rate achieved by the system; average cycle processing rate of a C[superscript]2 process, measured by the processing rate of the task circuit formed by a C[superscript]2 process; and the average system response time, measured by the average time elapsed for the system to perform an input were provided. Time and capacity constraints which are specific to characterize system behavior were addressed. The system effectiveness measures are represented and analyzed as a function of task processing time and capacity available to each process and the system. Hence, this makes it possible to analyze the system structure and thus modify the underlying system

    Electrically Robust Single-Crystalline WTe2 Nanobelts for Nanoscale Electrical Interconnects

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    As the elements of integrated circuits are downsized to the nanoscale, the current Cu-based interconnects are facing limitations due to increased resistivity and decreased current-carrying capacity because of scaling. Here, the bottom-up synthesis of single-crystalline WTe2 nanobelts and low- and high-field electrical characterization of nanoscale interconnect test structures in various ambient conditions are reported. Unlike exfoliated flakes obtained by the top-down approach, the bottom-up growth mode of WTe2 nanobelts allows systemic characterization of the electrical properties of WTe2 single crystals as a function of channel dimensions. Using a 1D heat transport model and a power law, it is determined that the breakdown of WTe2 devices under vacuum and with AlOx capping layer follows an ideal pattern for Joule heating, far from edge scattering. High-field electrical measurements and self-heating modeling demonstrate that the WTe2 nanobelts have a breakdown current density approaching approximate to 100 MA cm(-2), remarkably higher than those of conventional metals and other transition-metal chalcogenides, and sustain the highest electrical power per channel length (approximate to 16.4 W cm(-1)) among the interconnect candidates. The results suggest superior robustness of WTe2 against high-bias sweep and its possible applicability in future nanoelectronics

    Analysis of the C2 system effectiveness using continous processing time

    No full text
    A typical command-control (C[superscript]2) system was modeled and analyzed for peace-time and war-time as Conflict-free Stochastic Timed Placed Petri Net. The decomposition of the model provides an easier method to formulate and to simulate system states. The procedures to evaluate time-related measures: system maximum throughput rate, measured by minimum average circuit processing rate achieved by the system; average cycle processing rate of a C[superscript]2 process, measured by the processing rate of the task circuit formed by a C[superscript]2 process; and the average system response time, measured by the average time elapsed for the system to perform an input were provided. Time and capacity constraints which are specific to characterize system behavior were addressed. The system effectiveness measures are represented and analyzed as a function of task processing time and capacity available to each process and the system. Hence, this makes it possible to analyze the system structure and thus modify the underlying system.</p

    Strong Rashba parameter of two-dimensional electron gas at CaZrO3/SrTiO3 heterointerface

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    Abstract We synthesized a CaZrO3/SrTiO3 oxide heterostructure, which can serve as an alternative to LaAlO3/SrTiO3, and confirmed the generation of 2-dimensional electron gas (2-DEG) at the heterointerface. We analyzed the electrical-transport properties of the 2-DEG to elucidate its intrinsic characteristics. Based on the magnetic field dependence of resistance at 2 K, which exhibited Weak Anti-localization (WAL) behaviors, the fitted Rashba parameter values were found to be about 12–15 × 10–12 eV*m. These values are stronger than the previous reported Rashba parameters obtained from the 2-DEGs in other heterostructure systems and several layered 2D materials. The observed strong spin–orbit coupling (SOC) is attributed to the strong internal electric field generated by the lattice mismatch between the CaZrO3 layer and SrTiO3 substrate. This pioneering strong SOC of the 2-DEG at the CaZrO3/SrTiO3 heterointerface may play a pivotal role in the developing future metal oxide-based quantum nanoelectronics devices

    The impact of substrate surface defects on the properties of two-dimensional van der Waals heterostructures

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    The recent emergence of vertically stacked van der Waals (vdW) heterostructures provides new opportunities for these materials to be employed in a wide range of novel applications. Understanding the interlayer coupling in the stacking geometries of the heterostructures and its effect on the resultant material properties is particularly important for obtaining materials with desirable properties. Here, we report that the atomic bonding between stacked layers and thereby the interlayer properties of the vdW heterostructures can be well tuned by the substrate surface defects using WS2 flakes directly grown on graphene. We show that the defects of graphene have no significant effect on the crystal structure or the quality of the grown WS2 flakes; however, they have a strong influence on the interlayer interactions between stacked layers, thus affecting the layer deformability, thermal stability, and physical and electrical properties. Our experimental and computational investigations also reveal that WS2 flakes grown on graphene defects form covalent bonds with the underlying graphene via W atomic bridges (i.e., formation of larger overlapping hybrid orbitals), enabling these flakes to exhibit different intrinsic properties, such as higher conductivity and improved contact characteristics than heterostructures that have vdW interactions with graphene. This result emphasizes the importance of understanding the interlayer coupling in the stacking geometries and its correlation effect for designing desirable properties

    Substantial improvements of long-term stability in encapsulation-free WS2 using highly interacting graphene substrate

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    We report the novel role of graphene substrates in obstructing the aging propagation in both the basal planes and edges of two-dimensitional sheets of transition metal dichalcogenides (TMDs). Even after 300 d in ambient air conditions, the epitaxially grown WS2/graphene samples have a clean, uniform surface without any encapsulation. We show that high crystallinity is an effective factor that determines the excellent air stability of WS2/graphene, and we present impressive experimental evidence of the relation between defects and the aging phenomena. Moreover, we reveal the strong interlayer charge interaction as an additional factor for the enhanced air stability as a result of charge transfer-induced doping. This work not only proposes a simple method to create highly stable TMDs by the selection of a suitable substrate but also paves the way for the realization of practical TMDs-based applications.clos
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