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

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.

Four pages, no figures. This paper was submitted for publication to Phys. Rev. B in 8/05, and accepted for publication in 12/05. However, as a "Comment" on a previous paper, it is currently on hold with PRB awaiting submission and review of a "Reply" from the previous authors