531 research outputs found

    Committing to the Waves: Emerson\u27s Moving Assignments

    Full text link
    Committing to the Waves: Emerson\u27s Moving Assignments reads Ralph Waldo Emerson as a writer of assignments for living and working whose senses can be taken up across a wide array of creative and exploratory fields. Shifting between an interdisciplinary array of contexts ranging from philosophy and poetics to dance, performance, and somatic movement experiments, I join the practical sense of creative inquiry embodied in these fields to the abstract images of Emerson\u27s assignments. I argue that Emerson\u27s descriptions of intelligence and power, and so his approaches to navigating skepticism and loss, as well as the non-possessive sense of what self actually means to this thinker of self-reliance can be illuminated by reading from the non-dualist perspective that embodied inquiry offers. The dissertation also enacts the self-reliance that Emerson calls for by taking up my response to Emerson through my sense of his assignments. The first half of this study uses this embodied work as a resource for reading Emerson, situating his sense in relation to extra-literary and extra-philosophical research. The second half of the dissertation makes a pivot, taking Emerson as a resource for performance assignments, first in the form of a chapter written with poetic constraints, which approaches the question of how philosophical commitments might animate theater and actual performance, and finally by following Emerson\u27s instruction to the scholar to dive into her privatest presentiments to find where that privacy meets a public intelligence and intelligibility. The dissertation concludes with the documentation of Another Tree Dance, an original performance generated from that Emersonian private dive

    Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6

    Full text link
    As an exemplary Kondo insulator, SmB6 has been studied for several decades; however, direct evidence for the development of the Kondo coherent state and the evolution of the electronic structure in the material has not been obtained due to the rather complicated electronic and thermal transport behavior. Recently, these open questions attracted increasing attention as the emergence of a time-reversal invariant topological surface state in the Kondo insulator has been suggested. Here, we use point-contact spectroscopy to reveal the temperature dependence of the electronic states in SmB6. We demonstrate that SmB6 is a model Kondo insulator: below 100 K, the conductance spectra reflect the Kondo hybridization of Sm ions, but below ~ 30 K, signatures of inter-ion correlation effects clearly emerge. Moreover, we find evidence that the low-temperature insulating state of this exemplary Kondo lattice compound harbors conduction states on the surface, in support of predictions of nontrivial topology in Kondo insulators.Comment: Accepted for publication in Physical Review

    Spatially resolved femtosecond pump-probe study of topological insulator Bi2Se3

    Full text link
    Carrier and phonon dynamics in Bi2Se3 crystals are studied by a spatially resolved ultrafast pump-probe technique. Pronounced oscillations in differential reflection are observed with two distinct frequencies, and are attributed to coherent optical and acoustic phonons, respectively. The rising time of the signal indicates that the thermalization and energy relaxation of hot carriers are both sub-ps in this material. We found that the thermalization and relaxation time decreases with the carrier density. The expansion of the differential reflection profile allows us to estimate an ambipolar carrier diffusion coefficient on the order of 500 square centimeters per second. A long-term slow expansion of the profile shows a thermal diffusion coefficient of 1.2 square centimeters per second.Comment: 8 pages, 6 figure

    Terahertz Kerr and Reflectivity Measurements on the Topological Insulator Bi2Se3

    Full text link
    We report the first terahertz Kerr measurements on bulk crystals of the topological insulator Bi2Se3. At T=10K and fields up to 8T, the real and imaginary Kerr angle and reflectance measurements utilizing both linearly and circularly polarized incident radiation were measured at a frequency of 5.24meV. A single fluid free carrier bulk response can not describe the line-shape. Surface states with a small mass and surprisingly large associated spectral weight quantitatively fit all data. However, carrier concentration inhomogeneity has not been ruled out. A method employing a gate is shown to be promising for separating surface from bulk effects.Comment: 10 pages, 5 figure

    Magnetothermoelectric properties of Bi2Se3

    Get PDF
    We present a study of entropy transport in Bi2Se3 at low temperatures and high magnetic fields. In the zero-temperature limit, the magnitude of the Seebeck coefficient quantitatively tracks the Fermi temperature of the 3D Fermi surface at \Gamma-point as the carrier concentration changes by two orders of magnitude (1017^{17} to 1019^{19}cm−3^{-3}). In high magnetic fields, the Nernst response displays giant quantum oscillations indicating that this feature is not exclusive to compensated semi-metals. A comprehensive analysis of the Landau Level spectrum firmly establishes a large gg-factor in this material and a substantial decrease of the Fermi energy with increasing magnetic field across the quantum limit. Thus, the presence of bulk carriers significantly affects the spectrum of the intensively debated surface states in Bi2Se3 and related materials.Comment: 10 pages, 9 figure

    State of the Art Botnet-Centric Honeynet Design

    Get PDF
    The problem of malware has escalated at a rate that security professionals and researchers have been unable to deal with. Attackers savage the information technology (IT) infrastructure of corporations and governments with impunity. Of particular significance is the rise of botnets within the past ten years. In response, honeypots and honeynets were developed to gain critical intelligence on attackers and ultimately to neutralize their threats. Unfortunately, the malware community has adapted, and strategies used in the early half of the decade have diminished significantly in their effectiveness. This thesis explores the design characteristics necessary to create a honeynet capable of reversing the current trend and defeating botnet countermeasures. This thesis finds that anti-virtual machine detection techniques along with appropriate failsafes are essential to analyze modern botnet binaries
    • …
    corecore