Janutka Andrzej
Institute of Physics, Wroclaw University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 May;83(5 Pt 2):056607. doi: 10.1103/PhysRevE.83.056607. Epub 2011 May 17.
Analytical multidomain solutions to the dynamical (Landau-Lifshitz-Gilbert) equation of a one-dimensional ferromagnet including an external magnetic field and spin-polarized electric current are found using the Hirota bilinearization method. A standard approach to solve the Landau-Lifshitz equation (without the Gilbert term) is modified in order to treat the dissipative dynamics. I establish the relations between the spin interaction parameters (the constants of exchange, anisotropy, dissipation, external-field intensity, and electric-current intensity) and the domain-wall parameters (width and velocity) and compare them to the results of the Walker approximation and micromagnetic simulations. The domain-wall motion driven by a longitudinal external field is analyzed with especial relevance to the field-induced collision of two domain walls. I determine the result of such a collision (which is found to be an elastic one) on the domain-wall parameters below and above the Walker breakdown (in weak- and strong-field regimes). Single-domain-wall dynamics in the presence of an external transverse field is studied with relevance to the challenge of increasing the domain-wall velocity below the breakdown.
利用广田双线性化方法，找到了包含外磁场和自旋极化电流的一维铁磁体动力学（朗道 - 里夫希茨 - 吉尔伯特）方程的解析多域解。为了处理耗散动力学，对求解朗道 - 里夫希茨方程（无吉尔伯特项）的标准方法进行了修改。我建立了自旋相互作用参数（交换常数、各向异性常数、耗散常数、外场强度和电流强度）与畴壁参数（宽度和速度）之间的关系，并将它们与沃克近似和微磁模拟的结果进行比较。特别针对由纵向外场驱动的畴壁运动，分析了两个畴壁的场致碰撞。我确定了这种碰撞（发现是弹性碰撞）对沃克击穿上下（弱场和强场 regime）畴壁参数的影响。研究了存在外部横向场时的单畴壁动力学，这与在击穿以下提高畴壁速度的挑战相关。
