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New cooling mechanisms for atoms and molecules
No full textThe special issue of September 2011, Journal of Modern Optics, presents papers regarding the cooling of trapped atoms and ions to the micro and nanokelvin temperatures needed for quantum coherence and degeneracy. As part of this special issue, Wickenbrock and colleagues report the experimental verification of the collective enhancement of atom cavity interactions. Their experiment confines a large number N of cesium atoms with the help of a MOT inside an optical cavity. Liu and Yu present a theoretical study for cavity-based laser cooling of a V-type three level atom in a high-finesse optical cavity. Hemmerling and Robb investigate the possibility of cooling an atomic gas inside an optical cavity using blue-detuned laser light. The authors study two different scenarios, a cavity pump and an atom-pump configuration. Xuereb and co-researchers apply transfer matrix approach to atoms inside a ring cavity and show that it is possible to greatly improve the optomechanical force acting on a polarisable particle by using a gain medium to amplify the optical back-action.</p
Special issue in memory of Prof Danny Segal (1960-2015)
Full text linkThis special issue, on Quantum Optics, Cooling and Collisions of Ions and Atoms, is dedicated to the scientific interests of our much-loved and respected friend and colleague Danny Segal, whose research spanned many aspects of quantum and atomic physics, from PhD studies of atomic collision dynamics using pulsed dye lasers to his ultimate expertise with the long-lived coherence of cold trapped ions, which Danny hoped would one day lead to practical quantum information processing. The papers in this issue accordingly address topics ranging from precision laser spectroscopy to nonlinear optics, and from quantum optics to atom chips; its particular focus though is naturally upon trapped ions, their technologies, and the exciting science that they enabl
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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