3,074 research outputs found
The de Haas van Alphen effect near a quantum critical end point in Sr₃Ru₂O₇
No full textHighly correlated electron materials are systems in which many new states of matter can emerge. A particular situation which favours the formation of exotic phases of the electron liquid in complex materials is that where a quantum critical point (QCP) is present in the phase diagram. Neighbouring regions in parameter space reveal unusual physical properties, described as non-Fermi liquid behaviour.
One of the important problems in quantum criticality is to find out how the Fermi surface (FS) of a material evolves near a QCP. The traditional method for studying the FS of materials is the de Haas van Alphen effect (dHvA). A quantum critical end point (QCEP) has been reported in the highly correlated metal Sr₃Ru₂O₇, which is tuned using a magnetic field high enough to perform the dHvA experiment. It moreover features a new emergent phase in the vicinity of the QCEP, a nematic type of electron ordering.
The subject of this thesis is the study of the FS of Sr₃Ru₂O₇ using the dHvA effect. Three aspects were explored. The first was the determination of the FS at fields both above and below that where the QCEP arises. The second was the search for quantum oscillations inside the nematic phase. The third was a reinvestigation of the behaviour of the quasiparticle effective masses near the FS.
In collaboration with angle resolved photoemission spectroscopy experimentalists, a complete robust model for the FS of Sr₃Ru₂O₇ at zero fields was determined. Moreover, the new measurements of the quasiparticle masses revealed that no mass enhancements exist anywhere around the QCEP, in contradiction with previous specific heat data and measurements of the A coefficient of the power law of the resistivity. Finally, we report dHvA oscillations inside the nematic phase, and the temperature dependence of their amplitude suggests strongly that the carriers consist of Landau quasiparticles
The uniting of Europe and the foundation of EU studies: revisiting the neofunctionalism of Ernst B. Haas
No full textThis article suggests that the neofunctionalist theoretical legacy left by Ernst B. Haas is somewhat richer and more prescient than many contemporary discussants allow. The article develops an argument for routine and detailed re-reading of the corpus of neofunctionalist work (and that of Haas in particular), not only to disabuse contemporary students and scholars of the normally static and stylized reading that discussion of the theory provokes, but also to suggest that the conceptual repertoire of neofunctionalism is able to speak directly to current EU studies and comparative regionalism. Neofunctionalism is situated in its social scientific context before the theory's supposed erroneous reliance on the concept of 'spillover' is discussed critically. A case is then made for viewing Haas's neofunctionalism as a dynamic theory that not only corresponded to established social scientific norms, but did so in ways that were consistent with disciplinary openness and pluralism
Mehr Leben als Tod in Rom. Josef Winklers römische Novelle «Natura morta»
No full textThe essay’s introduction examines the importance of Italy for Josef Winkler and puts the novella «Natura morta» in context with his oeuvre. The subsequent analysis of the text highlights the technique used by the author, which shows similarities with the process of film shooting. The narrator’s eye follows the main character like a movie camera and is focused on numerous details as if it were zooming on them. In this process, while advancing the novella’s plot, the author paints a colorful portrait of Rome, bringing the city to
life like a baroque still life
A Translation Study of Silentium! by Wolf Haas
No full textabstract: Wolfgang Haas is an award-winning Austrian author known primarily for his entertaining and quirky detective novels which follow the misadventures of Simon Brenner, an Austrian private investigator. These novels are notable for their subtle and not-so-subtle critiques of contemporary Austrian society and culture, their sometimes grisly content, and their unique and colloquial use of the Austrian variety of the German language. Haas has received numerous literary awards in the German-speaking world and attributes his success to the unique way he tells his stories, rather than the stories themselves. Of the seven Brenner novels that have been published thus far, only one is available in English translation, and he remains virtually unknown in the English-speaking world. This thesis includes a brief biography of Haas and an overview of his career, an analysis of his unique writing style and the problems they pose for a translator, and an English translation of the first two chapters of the novel Silentium! (1999).Dissertation/ThesisM.A. German 201
Hollywood Film as Therapy: Hugo Haas, Trauma, and Survivor Guilt
No full textThe article discusses the exile cinema of Czechoslovakia-born producer, director, and actor Hugo Haas (1901–1968). As a prominent Jewish artist with strong anti-Nazi convictions, Haas was forced to escape his homeland when Hitler invaded Czechoslovakia in 1939. Deeply traumatized by losing his close relatives in the Holocaust, Haas used his independent productions made in Hollywood after World War II to cope with his feelings of loss, pain, loneliness, and dispossession. The author reads selected films, disguised as run-of-the-mill genre pieces, against the filmmaker’s personal history and identifies patterns and motives suggesting that Haas’s body of work was strongly informed by his survivor guilt and trauma
Evaluating tire/pavement noise utilizing the on-board sound intensity method
No full textMitigating transportation noise is a major concern for Departments of Transportation (DOT) nationwide. From a responsibility standpoint, once a noise source leaves the boundary of the property, the noise control falls under the jurisdiction of the DOT. In the past, mitigation by the DOT was typically accomplished by erecting a sound barrier. If there was more noise or louder noise, a larger wall was used. As construction of these walls is prohibitively expensive, DOTs are increasingly interested in mitigating noise from the source. In order to investigate noise being produced at the source, the on-board sound intensity method was utilized to investigate quiet pavements. The method revealed the acoustical properties of both conventional pavements and quiet pavements. This research also led to the investigation of the effects of vehicle speed, effects of temperature and effects of different consumer tires and the role each plays in the generation of noise at the tire pavement interface.M.S.Includes bibliographical referencesby Edwin H Haas II
The quantum mechanical origin of the Einstein-De Haas effect
No full textUnderstanding properties such as heat transfer coefficients in steels and how magnetic fields affect the microstructure and plasticity of reactor components is critical to both the materials selection process and the structural design of nuclear fusion tokamaks. Calculating these properties in ferromagnetic materials presents a challenge for modern computational materials science, since modelling the thermal effects in magnetic materials requires a description of spin-lattice coupling for systems involving large numbers of atoms. In this thesis, a noncollinear tight binding model capable of describing the coupling between spins and forces experienced by the lattice due the electrons is developed, which includes the effects of spin-orbit coupling, coupling to an external magnetic field, and vector Stoner
exchange. This model is used to investigate the Einstein-de Haas effect in the context of an O2 dimer and an Fe15 cluster. In both cases, an external time-varying magnetic field is found to produce a mechanical torque on the lattice nuclei, validating that the tight binding model is able to simulate the Einstein-de Haas effect.Open Acces
Haas-Molnar Continued Fractions and Metric Diophantine Approximation.
No full textHaas–Molnar maps are a family of maps of the unit interval introduced by A. Haas and D. Molnar. They include the regular continued fraction map and A. Renyi’s backward continued fraction map as important special cases. As shown by Haas and Molnar, it is possible to extend the theory of metric diophantine approximation, already well developed for the Gauss continued fraction map, to the class of Haas–Molnar maps. In particular, for a real number x, if (p n /q n )n≥1 denotes its sequence of regular continued fraction convergents, set θ n (x) = q 2n|x − p n /q n |, n = 1, 2.... The metric behaviour of the Cesàro averages of the sequence (θ n (x))n≥1 has been studied by a number of authors. Haas and Molnar have extended this study to the analogues of the sequence (θ n (x))n≥1 for the Haas–Molnar family of continued fraction expansions. In this paper we extend the study of n≥1 for certain sequences (k n )n≥1, initiated by the second named author, to Haas–Molnar maps
Observations of the de Haas-van Alpen Effect in Arsenic
No full textTitle: Observations of the de Haas-van Alpen Effect in Arsenic, Author: John Vanderkooy, Location: ThodeSemimetallic arsenic has been studied by magneto-resistance
methods and measurement of the de Haas-van Alphen effect using torque and magneto-thermal measurements. Several modifications have been made in the conventional torque techniques. An important cause of nonlinear effects in the torque experiments is presented and compared to other mechanisms for nonlinearities. The Fermi surface of arsenic as determined experimentally is shown to be in good agreement with recent
theoretical calculations which were partially guided by the experiments.ThesisDoctor of Philosophy (PhD
Shubnikov–de Haas Effect in the Metallic State of Na0.3CoO2
No full textShubnikov–de Haas oscillations for two well-defined frequencies, corresponding, respectively, to areas of 0.8 and 1.36% of the first Brillouin zone, were observed in single crystals of Na0.3CoO2. The existence of Na superstructures in Na0.3CoO2, coupled with this observation, suggests the possibility that the periods are due to the reconstruction of the large Fermi surface around the ? point. An alternative interpretation in terms of the long sought-after ?g? pockets is also considered but found to be incompatible with existing specific heat data.Kavli Institute of NanoscienceApplied Science
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