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On the critical dynamics of disordered spin systems

II. Shape Functions forT>T c

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Zeitschrift für Physik B Condensed Matter

Abstract

The shape functions, which determine the cross sectiond 2 σ/dEdΩ for the inelastic scattering of neutrons as a function of the energy lossℏω and momentum transferℏq, are calculated for the critical region aboveT c of disordered spin systems. The models considered are (i) systems with isotropic spin-spin interactions, but with a random variation of the exchange interaction, and (ii) models including additionally random local anisotropy directions. The dynamics is assumed to be either purely relaxational, or precessional, with nonconserved order parameter. The most prominent feature of the results, which are obtained by renormalization group techniques in 4—ε dimensions, is the appearence of a “central peak”, which is not present in the non disordered system.

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Authors and Affiliations

  1. Fachbereich Physik, Universität Regensburg, Universitätsstraße 31, D-8400, Regensburg, Federal Republic of Germany

    U. Krey

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  1. U. Krey
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Krey, U. On the critical dynamics of disordered spin systems. Z Physik B 27, 325–329 (1977). https://doi.org/10.1007/BF01320524

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  • DOI: https://doi.org/10.1007/BF01320524

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