Spin waves in paramagnetic bcc iron: spin dynamics simulations

Large scale computer simulations are used to elucidate a long-standing controversy regarding the existence, or otherwise, of spin waves in paramagnetic bcc iron. Spin dynamics simulations of the dynamic structure factor of a Heisenberg model of Fe with first principles interactions reveal that well...

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Bibliographic Details
Published inPhysical review letters Vol. 95; no. 8; p. 087207
Main Authors Tao, Xiuping, Landau, D P, Schulthess, T C, Stocks, G M
Format Journal Article
LanguageEnglish
Published United States 19.08.2005
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Summary:Large scale computer simulations are used to elucidate a long-standing controversy regarding the existence, or otherwise, of spin waves in paramagnetic bcc iron. Spin dynamics simulations of the dynamic structure factor of a Heisenberg model of Fe with first principles interactions reveal that well defined peaks persist far above Curie temperature Tc. At large wave vectors these peaks can be ascribed to propagating spin waves; at small wave vectors the peaks correspond to overdamped spin waves. Paradoxically, spin wave excitations exist despite only limited magnetic short-range order at and above Tc.
ISSN:0031-9007
DOI:10.1103/PhysRevLett.95.087207