29,307 research outputs found

    Does the 2D Hubbard Model Really Show d-Wave Superconductivity?

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    Some issues concerning the question if the two-dimensional Hubbard model really show d-wave superconductivity are briefly discussed.Comment: Revtex, no figure

    A Structured Framework and Resources to Use to Get Your Medical Education Work Published.

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    IntroductionMedical educators often have great ideas for medical education scholarship but have difficulty converting their educational abstract or project into a published manuscript.MethodsDuring this workshop, participants addressed common challenges in developing an educational manuscript. In small-group case scenarios, participants discovered the importance of the "So what?" in making the case for their project. Incorporating conceptual frameworks, participants chose appropriate outcome metrics, discussed how to frame the discussion section, and ensured appropriate journal fit. After each small-group exercise, large-group discussions allowed the small groups to report back so that facilitators could highlight and reinforce key learning points. At the conclusion of the workshop, participants left with a checklist for creating an educational manuscript and an additional resources document to assist them in avoiding common pitfalls when turning their educational abstract/project into a publishable manuscript.ResultsThis workshop was presented in 2016 and 2017. Presenter evaluations were completed by 33 participants; 11 completed conference evaluations. The mean overall rating on presenter evaluations was 4.55 out of 5, while the conference evaluations mean was 3.73 out of 4. Comments provided on both evaluation tools highlighted the perceived effectiveness of the delivery and content. More than 50% of respondents stated that they planned to incorporate the use of conceptual frameworks in future work.DiscussionThis workshop helped participants address common challenges by providing opportunities for hands-on practice as well as tips and resources for use when submitting a medical education manuscript for publication

    Antiferromagnetic Order in MnO Spherical Nanoparticles

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    We have performed unpolarized and polarized neutron diffraction experiments on monodisperse 8 nm and 13 nm antiferromagnetic MnO nanoparticles. For the 8 nm sample, the antiferromagnetic transition temperature TNT_N (114 K) is suppressed compared to the bulk material (119 K) while for the 13 nm sample TNT_N (120 K) is comparable to the bulk. The neutron diffraction data of the nanoparticles is well described using the bulk MnO magnetic structure but with a substantially reduced average magnetic moment of 4.2±\pm0.3 μB\mu_B/Mn for the 8 nm sample and 3.9±\pm0.2 μB\mu_B/Mn for the 13 nm sample. An analysis of the polarized neutron data on both samples shows that in an individual MnO nanoparticle about 80% of Mn ions order. These results can be explained by a structure in which the monodisperse nanoparticles studied here have a core that behaves similar to the bulk with a surface layer which does not contribute significantly to the magnetic order.Comment: 7 pages, 5 figure

    Field-Induced Transition in the S=1 Antiferromagnetic Chain with Single-Ion Anisotropy in a Transverse Magnetic Field

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    The field-induced transition in one-dimensional S=1 Heisenberg antiferromagnet with single-ion anisotropy in the presence of a transverse magnetic field is obtained on the basis of the Schwinger boson mean-field theory. The behaviors of the specific heat and susceptibility as functions of temperature as well as the applied transverse field are explored, which are found to be different from the results obtained under a longitudinal field. The anomalies of the specific heat at low temperatures, which might be an indicative of a field-induced transition from a Luttinger liquid phase to an ordered phase, are explicitly uncovered under the transverse field. A schematic phase diagram is proposed. The theoretical results are compared with experimental observations.Comment: Revtex, 7 figure

    Observation of surface states on heavily indium doped SnTe(111), a superconducting topological crystalline insulator

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    The topological crystalline insulator tin telluride is known to host superconductivity when doped with indium (Sn1−x_{1-x}Inx_{x}Te), and for low indium contents (x=0.04x=0.04) it is known that the topological surface states are preserved. Here we present the growth, characterization and angle resolved photoemission spectroscopy analysis of samples with much heavier In doping (up to x≈0.4x\approx0.4), a regime where the superconducting temperature is increased nearly fourfold. We demonstrate that despite strong p-type doping, Dirac-like surface states persist

    Debris Disks in NGC 2547

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    We have surveyed the 30 Myr-old cluster NGC 2547 for planetary debris disks using Spitzer. At 4.5-8 um we are sensitive to the photospheric level down to mid-M stars (0.2 Msol) and at 24 um to early-G stars (1.2 Msol). We find only two to four stars with excesses at 8 um out of ~400-500 cluster members, resulting in an excess fraction <~1 percent at this wavelength. By contrast, the excess fraction at 24 um is ~40 percent (for B-F types). Out of four late-type stars with excesses at 8 um two marginal ones are consistent with asteroid-like debris disks. Among stars with strong 8 um excesses one is possibly from a transitional disk, while another one can be a result of a catastrophic collision. Our survey demonstrates that the inner 0.1-1 AU parts of disks around solar-type stars clear out very thoroughly by 30 Myrs of age. Comparing with the much slower decay of excesses at 24 and 70 um, disks clear from the inside out, of order 10 Myr for the inner zones probed at 8 um compared with a hundred or more Myr for those probed with the two longer wavelengths.Comment: Accepted to ApJ, 29 pages, 13 figs. A Note in Proof concerning cluster's age was added in the original submission of 2007 July 19. Full Tables 1 and 2 in the electronic form together with the article with full resolution figures are available at http://www.astro.ufl.edu/~ngorlova/disksNGC2547

    Baryon wave function in large-Nc QCD: Universality, nonlinear evolution equation and asymptotic limit

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    The 1/Nc expansion is formulated for the baryon wave function in terms of a specially constructed generating functional. The leading order of this 1/Nc expansion is universal for all low-lying baryons [including the O(1/Nc) and O(Nc^0) excited resonances] and for baryon-meson scattering states. A nonlinear evolution equation of Hamilton-Jacobi type is derived for the generating functional describing the baryon distribution amplitude in the large-Nc limit. In the asymptotic regime this nonlinear equation is solved analytically. The anomalous dimensions of the leading-twist baryon operators diagonalizing the evolution are computed analytically up to the next-to-leading order of the 1/Nc expansion.Comment: 44 page
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