Probing Magnons by Spin-Polarized Electrons
Probing Magnons by Spin-Polarized Electrons
复制标题
通过自旋极化电子探测磁振子
DOI：
10.1007/978-3-642-30247-3_7
复制
发表时间：
2013
影响因子：
3.7
通讯作者：
J. Kirschner
中科院分区：
文献类型：
--
作者：
K. Zakeri;J. Kirschner
流动铁磁体中的高波矢量磁振子激发可以通过电子散射实验进行研究。在这样的实验中，具有明确能量的自旋偏振束从样品表面散射，并测量散射电子的能量分布。由于磁振子的总角动量为 1ħ，因此它们只能通过少数（多数）电子的入射而被激发（湮灭）。当少数（多数）电子入射时，这一事实导致强度谱的能量损失（增益）区域出现峰值。散射本身是弹性的，观察到的能量损失（或增益）是由于喷射的电子源于受激固体的较低（或较高）能级这一事实。这一过程是由纯库仑性质的交换相互作用介导的，不涉及显式的自旋-自旋相互作用。
High wave-vector magnon excitations in itinerant ferromagnets can be investigated by electron scattering experiments. In such an experiment, a spin-polarized beam with a well-defined energy is scattered from the sample surface and the energy distribution of the scattered electrons is measured. Since magnons possess a total angular momentum of 1ħ, they can only be excited (annihilated) by incidence of minority (majority) electrons. This fact leads to a peak in the energy loss (gain) region of the intensity spectra when minority (majority) electrons are incident. The scattering itself is elastic and the observed energy loss (or gain) is due to the fact that the ejected electron stems from a lower (or higher) energy level of the excited solid. Such a process is mediated by exchange interaction that is of a pure Coulomb nature and no explicit spin–spin interaction is involved.