Pereira Lucas Carvalho, do Nascimento Valter Aragão
Postgraduation Program in Materials Science, Institute of Physics, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil.
Group of Spectroscopy and Bioinformatics Applied to Biodiversity and Health, School of Medicine, Postgraduation Program in Health and Development in the Midwest Region, Faculty of Medicine, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, Mato Grosso do Sul, Brazil.
Materials (Basel). 2022 Mar 31;15(7):2551. doi: 10.3390/ma15072551.
In this paper, we theoretically investigate the stability of spin-wave solitons in Bose-Einstein condensates of repulsive magnons, confined by an inhomogeneous external magnetic field described by a Gaussian well. For this purpose, we use the quasi-one-dimensional Gross-Pitaevskii equation to describe the behavior of the condensate. In order to solve the Gross-Pitaevskii equation, we used two different approaches: one analytical (variational method) and another numerical (split-step Crank-Nicolson method). The stability of the solutions and the validation of the numerical results were confirmed, respectively, through the anti-VK criterion and the virial theorem. Furthermore, the simulations described the behavior of physical quantities of interest such as chemical potential, energy per magnon and central density as a function of the nonlinearity of the model (magnon-magnon interactions). The theoretical results provide subsidies for a better understanding of the nonlinear phenomena related to the Bose-Einstein condensates of magnons in ferromagnetic films.
在本文中，我们从理论上研究了由高斯阱描述的非均匀外磁场约束的排斥性磁振子玻色 - 爱因斯坦凝聚体中自旋波孤子的稳定性。为此，我们使用准一维格罗斯 - 皮塔耶夫斯基方程来描述凝聚体的行为。为了求解格罗斯 - 皮塔耶夫斯基方程，我们采用了两种不同的方法：一种是解析方法（变分法），另一种是数值方法（分步克兰克 - 尼科尔森方法）。分别通过反VK准则和维里定理证实了解的稳定性和数值结果的有效性。此外，模拟描述了诸如化学势、每个磁振子的能量和中心密度等感兴趣的物理量随模型非线性（磁振子 - 磁振子相互作用）的变化情况。理论结果为更好地理解铁磁薄膜中与磁振子玻色 - 爱因斯坦凝聚体相关的非线性现象提供了支持。
