9,560 research outputs found

    Sequential modular position and momentum measurements of a trapped ion mechanical oscillator

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    The non-commutativity of position and momentum observables is a hallmark feature of quantum physics. However this incompatibility does not extend to observables which are periodic in these base variables. Such modular-variable observables have been suggested as tools for fault-tolerant quantum computing and enhanced quantum sensing. Here we implement sequential measurements of modular variables in the oscillatory motion of a single trapped ion, using state-dependent displacements and a heralded non-destructive readout. We investigate the commutative nature of modular variable observables by demonstrating no-signaling-in-time between successive measurements, using a variety of input states. In the presence of quantum interference, which we enhance using squeezed input states, measurements of different periodicity show signaling-in-time. The sequential measurements allow us to extract two-time correlators for modular variables, which we use to violate a Leggett-Garg inequality. The experiments involve control and coherence of multi-component superpositions of up to 8 coherent, squeezed or Fock state wave-packets. Signaling-in-time as well as Leggett-Garg inequalities serve as efficient quantum witnesses which we probe here with a mechanical oscillator, a system which has a natural crossover from the quantum to the classical regime.Comment: 6 pages, 3 figures and supplemental informatio

    Laser driven self-assembly of shape-controlled potassium nanoparticles in porous glass

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    We observe growth of shape-controlled potassium nanoparticles inside a random network of glass nanopores, exposed to low-power laser radiation. Visible laser light plays a dual role: it increases the desorption probability of potassium atoms from the inner glass walls and induces the self-assembly of metastable metallic nanoparticles along the nanopores. By probing the sample transparency and the atomic light-induced desorption flux into the vapour phase, the dynamics of both cluster formation/evaporation and atomic photo-desorption processes are characterized. Results indicate that laser light not only increases the number of nanoparticles embedded in the glass matrix but also influences their structural properties. By properly choosing the laser frequency and the illumination time, we demonstrate that it is possible to tailor the nanoparticles'shape distribution. Furthermore, a deep connection between the macroscopic behaviour of atomic desorption and light-assisted cluster formation is observed. Our results suggest new perspectives for the study of atom/surface interaction as well as an effective tool for the light-controlled reversible growth of nanostructures.Comment: 14 pages,6 figures, http://iopscience.iop.org/1612-202X/11/8/085902

    Nootropics use in the workplace. Psychiatric and ethical aftermath towards the new frontier of bioengineering

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    OBJECTIVE: The authors have sought to expound upon and shed a light on the rise of nootropics, which have gradually taken on a more and more relevant role in workplaces and academic settings. MATERIALS AND METHODS: Multidisciplinary databases have been delved into by entering the following keys: "nootropics", "cognitive enhancement", "workplace", "productivity", "ethics", "bioengineering". In addition, a broad-ranging search has been undertaken on institutional websites in order to identify relevant analysis and recommendations issued by international institutions and agencies. Papers and reports have been independently pored over by each author. This search strategy has led to the identification of 988 sources but only 64 were considered appropriate for the purposes of the paper after being selected by at least 3 of the authors, independently. RESULTS: The notion of an artificially enhanced work performance - carried out by the 'superworker' - is particularly noteworthy and resonates with the conception of contemporary work on so many different levels: the rising need and demands for higher degrees of flexibility and productivity on the job, the implications of a '24/7' society, where more and more services are available at any time, the ever greater emphasis on entrepreneurial spirit, individual self-reliance and self-improvement, and last but not least, the impact of an ageing society on economic standards and performance. CONCLUSIONS: Moreover, it is worth mentioning that human enhancement technologies will predictably and increasingly go hand in hand with gene editing, bioengineering, cybernetics and nanotechnology. Applications are virtually boundless, and may ultimately affect all human traits (physical strength, endurance, vision, intelligence and even personality and mood)

    Absolute Continuity of Solutions to Reaction-Diffusion Equations with Multiplicative Noise

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    We prove absolute continuity of the law of the solution, evaluated at fixed points in time and space, to a parabolic dissipative stochastic PDE on L (G), where G is an open bounded domain in ‚ĄĚ with smooth boundary. The equation is driven by a multiplicative Wiener noise and the nonlinear drift term is the superposition operator associated to a real function that is assumed to be monotone, locally Lipschitz continuous, and growing not faster than a polynomial. The proof, which uses arguments of the Malliavin calculus, crucially relies on the well-posedness theory in the mild sense for stochastic evolution equations in Banach spaces. 2

    La liberalidad hoy. Los contenidos básicos comunes de formación ética y ciudadana en la EGB en la reforma educativa argentina

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    La proliferaci√≥n de conceptos √©ticos que observamos en la modernidad, junto con el aumento de la equivocidad entre muchos de ellos, no contribuyen a clarificar y orientar la acci√≥n moral, ni la educaci√≥n encaminada a ella. En este art√≠culo, en una primera parte, tratamos de precisar uno de esos conceptos, el de liberalidad y su posici√≥n respecto a t√©rminos pr√≥ximos y concomitantes tales como la solidaridad, la generosidad, el respeto y la tolerancia. En la segunda parte, nos centramos en ver en qu√© medida est√° presente la promoci√≥n de esta virtud social ‚ÄĒla liberalidad‚ÄĒ en la propuesta de Formaci√≥n √Čtica y Ciudadana que la reforma educativa argentina (1993), concretamente en los Contenidos B√°sicos Comunes, sugiere. Se concluye subrayando la necesidad de profundizar en un marco te√≥rico adecuado en el que est√©n presentes las virtudes sociales aunque sin ninguna duda, la propuesta que la Ley Federal de Educaci√≥n nos ofrece constituye una base aceptable de discusi√≥n e investigaci√≥n presente y futura.---------------------The proliferation of ethical concepts that can be found in modem thinking, together with the increasing confusion between them, make no contribution for defining clear guide fines for moral action: nor moral education. The aim of this paper is to contribute to a more accurate definition of one of these concepts, liberality, and their relation to related notions such as solidarity, generosity, respect for others, and above all, tolerance. Then we focus on the presence of this social virtue within the project of Ethical and Civic Education in the 1993 Argentinian Education Bill. The conclusions underline the need for an adequate theoretical frame. In this regard, the "Ley Federal de Educacion" offers an interesting basis, for discussion and practical and research development

    Teams in New Ventures: Gender, Human Capital and Motivation

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    Purpose- This paper dismantles the idea that sex per se explains entrepreneurial outcomes and demonstrates the influence of a gendered motivation on forging and shaping new venture teams, which is a disruptive choice affecting the future of start-ups. Methods- A two-level research model is validated on data from the PSED II, with a system of simultaneous equations. Firstly, we test if team features affect the performance of new ventures; then, we investigate determinants of team features with a focus on sex and motivation of nascent entrepreneurs. Findings- Human capital (HC) in terms of education and experience of team members consistently explains venture evolution only when considering the larger team of affiliates. The HC gathered by nascent entrepreneurs is not due to the simplistic sex condition, but rather to a gendered motivation related to the inferior need of achievement of women. Research limitations- Limitations of discretionary scoring assigned to items of the PSED II survey are present, but unavoidable when processing qualitative data. Social and Practical implications- Women need to be (culturally) educated on how to re-balance their personal motivation towards entrepreneurship by fostering their incentives for achievement. Political and educational programs could trigger success in the creation of new businesses led by women. Originality/value- This paper contributes to the literature on nascent entrepreneurship, focusing on the entrepreneurial teams in the initial phase of business creation, and provides the basis for further studies aimed at eradicating the stereotypes of gender roles that lead women to self-exclusion and organizational errors

    An alternative proof of well-posedness of stochastic evolution equations in the variational setting

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    We present a new proof of well-posedness of stochastic evolution equations in variational form, relying solely on a (nonlinear) infinite-dimensional approximation procedure rather than on classical finite-dimensional projection arguments of Galerkin type
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