论文标题
结合分子和自旋动力学的爱因斯坦 - de haas效应的仿真
Simulation of the Einstein-de Haas effect combining molecular and spin dynamics
论文作者
论文摘要
通过分子动力学和半古典旋转动力学模拟研究了铁磁纳米颗粒的自旋和晶格动力学，其中自旋和晶格自由度通过动态单轴各向异性术语耦合。我们表明，该模型可以节省总角动量，而自旋和晶格角动量不能保守。我们使用开源的Spinlattice Dynamics Code（Spilady）进行了500多个原子的Fe纳米群集的Einstein-De Haas效应模拟。我们表明，自旋和晶格之间的角动量转移速率与磁各向异性相互作用的强度成正比。各向异性的添加允许在先前报道的\ sim 100 ps的时间尺度上以及与小型纳米群落相当的紧密结合磁各向异性能量上实现完全自旋晶格弛豫。
The spin and lattice dynamics of a ferromagnetic nanoparticle are studied via molecular dynamics and with semi-classical spin dynamics simulations where spin and lattice degrees of freedom are coupled via a dynamic uniaxial anisotropy term. We show that this model conserves total angular momentum, whereas spin and lattice angular momentum are not conserved. We carry out simulations of the the Einstein-de Haas effect for a Fe nanocluster with more than 500 atoms that is free to rotate, using a modified version of the open-source spinlattice dynamics code (SPILADY). We show that the rate of angular momentum transfer between spin and lattice is proportional to the strength of the magnetic anisotropy interaction. The addition of the anisotropy allows full spin-lattice relaxation to be achieved on previously reported timescales of \sim 100 ps and for tight-binding magnetic anisotropy energies comparable to those of small Fe nanoclusters.
