论文标题
自旋偏振热电子传输与由局部加热介导的自旋泵送
Spin-polarized hot electron transport versus spin pumping mediated by local heating
论文作者
论文摘要
提出了一种旨在捕获基本物理学的“玩具模型”，该模型共同描述了自旋偏振热电子传输和由局部加热驱动的自旋泵送。这两个过程都导致激光激光磁异质结构的自旋产生。该模型用于直接比较这两个贡献。自旋偏振热电子电流被建模为具有自旋依赖性激发和松弛方案的一代热电子。衰减后，热电子的过量能量被转移到热电子浴中。升高的电子温度导致电子磁通散射过程的增加，并产生局部自旋的积累。此过程被称为通过局部加热来称为自旋泵送。通过（界面）电子传输有效地从铁磁系统中驱动了构建的自旋积累。在我们的模型中，注入的自旋电流由自旋泵送产生的贡献支配，而热电子自旋电流保持相对较小。我们得出该观察结果与费米温度和居里温度之间的比率有关，并且我们显示了其他基本参数起着哪些作用。
A `toy model' - aimed at capturing the essential physics - is presented that jointly describes spin-polarized hot electron transport and spin pumping driven by local heating. These two processes both contribute to spin-current generation in laser-excited magnetic heterostructures. The model is used to compare the two contributions directly. The spin-polarized hot electron current is modeled as one generation of hot electrons with a spin-dependent excitation and relaxation scheme. Upon decay, the excess energy of the hot electrons is transferred to a thermalized electron bath. The elevated electron temperature leads to an increased rate of electron-magnon scattering processes and yields a local accumulation of spin. This process is dubbed as spin pumping by local heating. The built-up spin accumulation is effectively driven out of the ferromagnetic system by (interfacial) electron transport. Within our model, the injected spin current is dominated by the contribution resulting from spin pumping, while the hot electron spin current remains relatively small. We derive that this observation is related to the ratio between the Fermi temperature and Curie temperature, and we show what other fundamental parameters play a role.
