Dresden 2017 – wissenschaftliches Programm
MA 27.4: Vortrag
Dienstag, 21. März 2017, 14:45–15:00, HSZ 301
Spin-torque Effects in Thermally Assisted Magnetization Reversal: Kramers' Escape Rate Theory Approach — Yuri P. Kalmykov1, Declan J. Byrne2, •William T. Coffey3, William J. Dowling3, Sergey V. Titov4, and Jean Eric Wegrowe5 — 1Univ. Perpignan Via Domitia, Laboratoire de Mathématiques et Physique, F-66860, Perpignan, France — 2School of Physics, University College Dublin, Belfield, Dublin 4, Ireland — 3Department of Electronic and Electrical Engineering, Trinity College, Dublin 2, Ireland — 4Kotel'nikov Institute of Radio Engineering and Electronics of the Russian Academy of Sciences, Vvedenskii Square 1, Fryazino, Moscow Region, 141120, Russia — 5Laboratoire des Solides Irradiés, Ecole Polytechnique, 91128 Palaiseau Cedex, France
Thermal fluctuations of nanomagnets driven by spin-polarized currents are treated via the Landau-Lifshitz-Gilbert equation generalized to include both the random thermal noise field and the Slonczewski spin-transfer torque (STT) term. The reversal time of the magnetization in such a nanomagnet are evaluated for wide ranges of damping by using the method of Coffey et al. [Phys. Rev. E 63, 021102 (2001)]. Their method generalizes the Mel'nikov-Meshkov approach [J. Chem. Phys. 85, 1018 (1986)] for bridging the very low damping (VLD) and intermediate damping (ID) Kramers escape rates for mechanical Brownian particles (the Kramers turnover problem) to the analogous magnetic turnover problem.