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Comment on "Fluctuation-dissipation considerations and damping models for ferromagnetic thin-films"

Neil Smith
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Abstract

In a recent article (Phys. Rev. B 71, 224402 (2005)), Safonov and Bertram claim "inconsistent" results can occur when applying the "Callen-Welton fluctuation dissipation theorem" to magnetic systems with dissipation. This author strongly disputes these claims, and instead will show that the inconsistencies claimed by Safonov and Bertram stem solely from a failure to correctly complete a linear transformation of variables, and a concomitant invalid application of well known fluctuation dissipation relations. When used correctly, such fluctuation-dissipation relations most certainly will apply to magnetic (or other physical) systems with dissipation.

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Neil Smith. 2006-02-23. Comment on "Fluctuation-dissipation considerations and damping models for ferromagnetic thin-films". https://doi.org/10.1103/physrevb.74.026401

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