1,720,955 research outputs found
Field-Induced Boson Insulating States in a 2D Superconducting Electron Gas with Strong Spin-Orbit Scatterings
Get PDFThe phenomenon of field-induced superconductor-to-insulator transitions
observed experimentally in electron-doped SrTiO/LaAlO interfaces,
analyzed recently by means of 2D superconducting fluctuations theory (Phys.
Rev. B \textbf{104}, 054503 (2021)), is revisited with new insights associating
it with the appearance at low temperatures of field-induced boson insulating
states. Within the framework of the time-dependent Ginzburg-Landau functional
approach, we pinpoint the origin of these states in field-induced extreme
softening of fluctuation modes over a large region in momentum space, upon
diminishing temperature, which drives Cooper-pair fluctuations to condense into
mesoscopic puddles in real space. Dynamical quantum tunneling of Cooper-pair
fluctuations out of these puddles, introduced within a phenomenological
approach, which break into mobile single-electron states, contains the
high-field resistance onset predicted by the exclusive boson theory.Comment: arXiv admin note: substantial text overlap with arXiv:2201.0115
Microscopic Theory of Cooper-pair fluctuations in a 2D Electron System with Strong Spin-Orbit Scatterings: Crossover to Phase Separation and Large Magnetoresistance
Get PDFA microscopic theory of Cooper-pair fluctuations (CPFs) in a 2D electron
system with strong spin-orbit scatterings is presented to account for the
observation, at low temperatures, of large magnetoresistance (MR) above a
crossover field to superconductivity in electron-doped SrTiO/LaAlO
interfaces. It is found that the conventional (diagrammatic) microscopic theory
of superconducting fluctuations yields corrections to the normal-state
conductivity too small to account for the pronounced MR. However, an extension
of the theory, which introduces a proper definition of the CPFs density,
reveals an operative mechanism of this intriguing large MR. A crossover to
phase separation, due to Coulomb repulsion, between the rarefying unpaired
normal-state electron gas and condensates of CPFs in real-space mesoscopic
puddles, developed under increasing field, drive a crossover to a large MR. In
the framework of this scenario it is possible to amend the state-of-the-art
microscopic theory consistently with the time dependent Ginzburg-Landau
functional approach, used previously in an extensive account of the
experimentally reported effect.Comment: 21 pages, 4 figure
Self-consistent Bogoliubov-de Gennes theory of the vortex lattice state in a two-dimensional strongly type-II superconductor at high magnetic fields
No full textA self-consistent Bogoliubov-de Gennes theory of the vortex lattice state in a 2D strong type-II superconductor at high magnetic fields reveals a novel quantum mixed state around the semiclassical H-c2, characterized by a well-defined Landau-Bloch band structure in the quasiparticle spectrum and suppressed order-parameter amplitude, which sharply crossover into the well-known semiclassical (Helfand-Werthamer) results upon decreasing magnetic field. Application to the 2D superconducting state observed recently on the surface of the topological insulator Sb2Te3 accounts well for the experimental data, revealing a strong type-II superconductor, with unusually low carrier density and very small cyclotron mass, which can be realized only in the strong coupling superconductor limit.E. Bishop and J. Bishop research fund at TechnionSCI(E)ARTICLE29
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
