Ultrafast spin dynamics: the effect of colored noise

Phys Rev Lett. 2009 Feb 6;102(5):057203. doi: 10.1103/PhysRevLett.102.057203. Epub 2009 Feb 3.

Abstract

Recent experimental results have pushed the limits of magnetization dynamics to pico- and femtosecond time scales. This ultrafast dynamics occurs in extreme conditions of strong and rapid fields and high temperatures. This situation requires a new description of magnetization dynamics, taking into account that the electron correlation time could be of the order of the inverse spin frequency. For this case we introduce a thermodynamically correct phenomenological Landau-Lifshitz-Miyasaki-Seki approach. We demonstrate the effect of the noise correlation time on the ultrafast demagnetization rate.