1,720,960 research outputs found
Magnetic Field Induced Phases in Kitaev Magnets: A Semiclassical Analysis
Get PDFThe Kitaev honeycomb model is a rare example of exactly soluble S=1/2 frustrated systems with a quantum spin liquid ground state, in which the spins fractionalize into Majorana fermions coupled to a ℤ2 gauge field. The bond dependent Ising interaction that defines the Kitaev honeycomb model is proposed to have a dominant presence in transition metal compounds with partially filled d orbitals and a strong spin-orbit coupling. However, these materials, which are known as Kitaev magnets, generically possess other interactions such that a magnetically ordered ground state is stabilized, instead of the desired Kitaev spin liquid. Intriguingly, recent experiments on the Kitaev magnet α-RuCl3 subjected to external magnetic fields reported a half-quantized thermal Hall effect and a neutron scattering continuum, hinting at a field induced quantum spin liquid. Motivated by these experiments, we theoretically investigate the possible emergent phases in realistic spin models of Kitaev magnets under a magnetic field, via a semiclassical analysis. We identify phases other than the Kitaev spin liquid that are able to account for some of the experimental observations. In particular, we show that the thermal Hall conductivity due to magnons in the polarized state exhibits the same sign structure as in the suspected spin liquid phase, while the energy spectra of magnetic orders with large unit cells resemble an excitation continuum. We also discuss an instance of how the classical S → ∞ model helps us to understand its quantum S=1/2 counterpart, by establishing a correspondence between two phases found in the opposite limits. Finally, we conclude our studies and suggest some potential future research directions.Ph.D
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
Topological phase diagrams of in-plane field polarized Kitaev magnets
Get PDFWhile the existence of a magnetic field induced quantum spin liquid in Kitaev
magnets remains under debate, its topological properties often extend to
proximal phases where they can lead to unusual behaviors of both fundamental
and applied interests. Subjecting a generic nearest neighbor spin model of
Kitaev magnets to a sufficiently strong in-plane magnetic field, we study the
resulting polarized phase and the associated magnon excitations. In contrast to
the case of an out-of-plane magnetic field where the magnon band topology is
enforced by symmetry, we find that it is possible for topologically trivial and
nontrivial parameter regimes to coexist under in-plane magnetic fields. We map
out the topological phase diagrams of the magnon bands, revealing a rich
pattern of variation of the Chern number over the parameter space and the field
angle. We further compute the magnon thermal Hall conductivity as a weighted
summation of Berry curvatures, and discuss experimental implications of our
results to planar thermal Hall effects in Kitaev magnets.Comment: 7+12 pages, 4+5 figures, 1+0 table; published versio
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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