1,720,979 research outputs found
Cryogenic characterization and modeling of a CMOS floating-gate device for quantum control hardware
Full text linkWe perform the characterization and modeling of a floating-gate device realized with a commercial 350-nm CMOS technology at cryogenic temperature. The programmability of the device offers a solution in the realization of a precise and flexible cryogenic system for qubits control in large-scale quantum computers. The device stores onto a floating-gate node a non-volatile charge, which can be bidirectionally modified by Fowler-Nordheim tunneling and impact-ionized hot-electron injection. These two injection mechanisms are characterized and modelled in compact equations both at 300 K and 15 K. At cryogenic temperature, we show a fine-tuning of the stored charge compatible with the operation of a precise analog memory. Moreover, we developed accurate simulation models of the proposed floating-gate device that set the stage for designing a programmable analog circuit with better performances and accuracy at a few Kelvin. This work offers a solution in the design of configurable analog electronics to be employed for accurately read out the qubit state at deep-cryogenic temperature
Floating-gate transistor at cryogenic temperature: Characterization and modelling of tunnelling and hot electrons injection
No full textWe demonstrate the cryogenic operation of a floating-gate device fabricated using an inexpensive commercial CMOS process. Device architecture and basic characteristics at 15K and at room temperature are presented. A fine tuning of the stored charge is obtained by combining channel hot electron injection and Fowler-Nordheim tunneling. This programmability is compatible with an operation of the proposed floating-gate as long-term accurate analog memory, as required by cryogenic neuromorphic systems or precise analog circuits operating at few Kelvin
Fully-integrated data acquisition system operating at cryogenic temperature for semiconductor qubits
No full textCompact and scalable quantum computer required physical qubits with low footprint and cryogenic electronics to be used in situ as standard control/readout system. The small spatial gap between the quantum chip and the cryogenic electronics limits the complexity of the wiring connections and the associated stray capacitance of the wires themselves, yielding a gain in terms of bandwidth and resolution. These improvements allow to design a fully-integrated CMOS readout based on current measurements with similar performances compared to the most common RF reflectometry-based readout technique. Here, we propose an acquisition system, operating at 4.2 K, which converts the spin dependent current coming from a single-electron transistor charge sensor into a digital output with a small power consumption (1 mW/qubit) and small occupation area (< 1 mm(2)). The system on chip consists of a low noise active integrator for the spin current, feeding a programmable threshold comparator to provide a digital output of the qubit state. It exhibits a resolution of tens of pA over an average input current of 1 nA with a time resolution of 1 mu s.Compared to spin-qubit readout based on RF-reflectometry techniques, our solution does not require bulky off-chip components and to handle microwave signal and fast analog-to digital converters
Datazione di reperti archeologici provenienti dal sito Serra di Cristo (Biccari, FG) tramite misure di Termoluminescenza
No full textDisentangling the corporate entrepreneurship construct: conceptualizing through co-words
Full text linkThis study defines the conceptual structure of corporate entrepreneurship (CE) by looking at the terms scholars have used over the last 26 years of research. With the use of a co-word analysis, five distinctive dimensions of CE and the evolution of related key terms are identified: sustained regeneration, competitive advantage, external entrepreneurship, organizational rejuvenation, and domain redefinition. Over time scholars’ attention has shifted from strategy to entrepreneurship by highlighting the relevance of the terms ‘intrapreneurship’ and ‘entrepreneurial orientation’. Surprisingly, concepts related to strategic entrepreneurship and strategic renewal are less relevant than expected. Besides laying the ground for a shared conceptualization of CE, this study highlights how bibliomeitrics can contribute to decreasing conceptual ambiguity in emergent research fields, such as entrepreneurship. Implications for managers on how to strategically create and develop CE within different organizational settings are also discussed
Fully CMOS integrated programmable charge-to-digital readout operating at cryogenic temperature for semiconductor qubits
No full textWe present a compact CMOS readout electronics for spin qubits based on the single-electron transistor (SET) current measurement. The spin-state to digital conversion consists of integrating the current of the SET used for the spin to charge conversion feeding a programmable threshold comparator to provide a digital output of the qubit state. We achieve a microsecond time resolution with a 1 mW power consumption at 4.2 K.Compared to RF reflectometry-based readout, our solution does not require off-chip components allowing a reduction of the power consumption and the occupation area
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
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
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