1,720,989 research outputs found
Advances in molecular quantum computing: From technological modeling to circuit design
Full text linkMolecules are serious candidates for building hardware for quantum computers. They can encode quantum information onto electron or nuclear spins and some of them show important features as the scalability of the number of qubits and a universal set of quantum gates. In this paper we present our advances in the development of a classical simulation infrastructure for molecular Quantum Computing: starting from the definition of simplified models taking into account the main physical features of each analyzed molecule, quantum gates are defined over these models, thus permitting to take into account the real behavior of each technology during the simulation. An interface with a hardware-agnostic description language has been also developed. The knowledge of the behavior of real systems permits to optimize the design of quantum circuits at both physical and compilation levels. Elementary quantum algorithms have been simulated on three different molecular technologies by changing the physical parameters of polarization and manipulation and quantum circuit design strategies. Results confirm the dependency of the fidelity of the results on both levels, thus proving that the choice of optimal operating points and circuit optimization techniques as virtual-Z gates are fundamental for ensuring the execution of quantum circuits with negligible errors
SCERPA Simulation of Clocked Molecular Field-Coupling Nanocomputing
Full text linkAmong all the possible technologies proposed for post-CMOS computing, molecular field-coupled nanocomputing (FCN) is one of the most promising technologies. The information propagation relies on electrostatic interactions among single molecules, overcoming the need for electron transport, significantly reducing energy dissipation. The expected working frequency is very high, and high throughput may be achieved by introducing an efficient pipeline of information propagation. The pipeline could be realized by adding an external clock signal that controls the propagation of data and makes the transmission adiabatic. In this article, we extend the Self-Consistent Electrostatic Potential Algorithm (SCERPA), previously introduced to analyze molecular circuits with a uniform clock field, to clocked molecular devices. The single-molecule is analyzed by ab initio calculations and modeled as an electronic device. Several clocked devices have been partitioned into clock zones and analyzed: the binary wire, the bus, the inverter, and the majority voter. The proposed modification of SCERPA enables linking the functional behavior of the clocked devices to molecular physics, becoming a possible tool for the eventual physical design verification of emerging FCN devices. The algorithm provides some first quantitative results that highlight the clocked propagation characteristics and provide significant feedback for the future implementation of molecular FCN circuits
AEQUAM: Accelerating Quantum Algorithm Validation through FPGA-Based Emulation
Full text linkThis work presents AEQUAM (Area Efficient QUAntum eMulation), a toolchain that enables faster and more accessible quantum circuit verification. It consists of a compiler that translates OpenQASM 2.0 into RISC-like instructions, Cython software models for selecting number representations and simulating circuits, and a VHDL generator that produces RTL descriptions for FPGA-based hardware emulators. The architecture leverages a SIMD approach to parallelize computation and reduces complexity by exploiting the sparsity of quantum gate matrices. The VHDL generator allows customization of the number of emulated qubits and parallelization levels to meet user requirements. Synthesized on an Altera Cyclone 10LP FPGA with a 20-bit fixed-point representation and nearest-type approximation, the architecture demonstrates better scalability than other state-of-the-art emulators. Specifically, the emulator has been validated by exploiting the well consolidated benchmark of mqt bench framework
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Exploiting the Logic-In-Memory paradigm for speeding-up data-intensive algorithms
Full text linkIn the last decades transistor scaling has driven electronics toward an extraordinary evolution. The ability to squeeze millions of transistors on a single chip makes it possible to have an incredible computational power in very small size. Many computational systems are still based on the Von Neumann architecture, where computational units and memory blocks are two separate entities. Nanometer-sized transistors enable the development of incredibly fast logic units that cannot work at full speed due to limitations in data transfer from memory. To further evolve electronic circuits, new innovative architectural solutions must be developed to overcome the main limitations of current systems. In this work, we present an architectural implementation of the Logic-In-Memory (LIM) concept that we characterize by considering three data-intensive benchmarks: the odd even sort, the integral image and the binomial filter. The architecture is synthesized on a 28 nm CMOS technology and it is validated by comparing it to a previous version of the LIM structure and to conventional architectures, showing an impressive increase in performance, in terms of speed gain and power consumption reduction
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Topology optimization and Monte Carlo multithreading simulation for fault-tolerant nanoarrays
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