论文标题
用Fept为femto-hompo-hompo-hago磁性
Making a case for femto- phono- magnetism with FePt
论文作者
论文摘要
在灾难磁性的领域，磁性物质由超快激光脉冲控制；在这里，我们表明，将核的声子激发旋转和电荷的耦合导致femto-phono-ragnetism，这是一种在超快时间控制磁性的强大途径。通过对耦合自旋，电荷和晶格 - 动力学的最新理论模拟，我们确定了强大的非绝热旋转phonon耦合模式，这些模式主导了早期时间旋转动力学。激活这些声子模式，我们显示的导致在泵激光脉冲40秒内发生的FEPT中额外（最多40 \％额外）的力矩损失。支持这种增强的超快自旋力矩损失的基础，我们确定了一种物理机制，在这种机制中，少数旋转驱动了增强的地点间少数族裔电荷转移，进而促进了现场自旋倾角的增加。我们的发现表明，通常假定仅扮演能量下沉的作用的核系统可以在旋转系统中长期重新融化，可以在控制材料中的飞秒旋转动力学方面发挥着重要作用。
In the field of femtomagnetism magnetic matter is controlled by ultrafast laser pulses; here we show that coupling phonon excitations of the nuclei to spin and charge leads to femto-phono-magnetism, a powerful route to control magnetic order at ultrafast times. With state-of-the-art theoretical simulations of coupled spin-, charge-, and lattice-dynamics we identify strong non-adiabatic spin-phonon coupled modes that dominate early time spin dynamics. Activating these phonon modes we show leads to an additional (up to 40\% extra) loss of moment in FePt occurring within 40 femtoseconds of the pump laser pulse. Underpinning this enhanced ultrafast loss of spin moment we identify a physical mechanism in which minority spin-current drives an enhanced inter-site minority charge transfer, in turn promoting increased on-site spin flips. Our finding demonstrates that the nuclear system, often assumed to play only the role of an energy sink aiding long time re-magnetisation of the spin system, can play a profound role in controlling femtosecond spin-dynamics in materials.
