Microscopic model for ultrafast remagnetization dynamics.
Microscopic model for ultrafast remagnetization dynamics.
复制标题
DOI：
10.1103/physrevlett.109.157201
复制
发表时间：
2012-10
影响因子：
8.6
通讯作者：
R. Chimata;A. Bergman;L. Bergqvist;B. Sanyal;O. Eriksson
中科院分区：
文献类型：
--
作者：
R. Chimata;A. Bergman;L. Bergqvist;B. Sanyal;O. Eriksson
在这封信中，我们提供了一个微观模型，用于描述已经通过强激光注量淬火到斯通纳-居里温度以上的原子矩的超快再磁化。结合第一性原理密度泛函理论、利用 Landau-Lifshitz-Gilbert 方程的原子自旋动力学和三温度模型，我们分析了原子矩的时间演化以及 bcc Fe 和 hcp Co 的宏观磁化强度，涵盖从飞秒到皮秒的广泛时间尺度。我们的模拟显示了由于电子、自旋和晶格子系统之间的相互作用而产生的各种复杂的磁特性时间行为，这导致了原子矩复杂的时间演化，其中纵向和横向波动导致高度非单调演化的宏观自旋矩。
In this Letter, we provide a microscopic model for the ultrafast remagnetization of atomic moments already quenched above the Stoner-Curie temperature by a strong laser fluence. Combining first-principles density functional theory, atomistic spin dynamics utilizing the Landau-Lifshitz-Gilbert equation, and a three-temperature model, we analyze the temporal evolution of atomic moments as well as the macroscopic magnetization of bcc Fe and hcp Co covering a broad time scale, ranging from femtoseconds to picoseconds. Our simulations show a variety of complex temporal behavior of the magnetic properties resulting from an interplay between electron, spin, and lattice subsystems, which causes an intricate time evolution of the atomic moment, where longitudinal and transversal fluctuations result in a macrospin moment that evolves highly nonmonotonically.