[PDF] Ultrafast dynamics of electrons excited by femtosecond laser pulses: spin polarization and spin-polarized currents-论文阅读讨论-ReadPaper

摘要

Laser radiation incident on a ferromagnetic sample produces excited electronsand currents whose spin polarization must not be aligned with the magnetization-- an effect due to spin-orbit coupling that is ubiquitous in spin- andangle-resolved photoemission. In this Paper, we report on a systematicinvestigation of the dynamics of spin polarization and spin-polarized currentsproduced by femtosecond laser pulses, modeled within our theoretical frameworkEVOLVE. The spin polarization depends strongly on the properties of the laserpulse and on the sample composition, as is shown by comparing results forCu(100), Co(100), and a Co/Cu heterostructure. We find a transition fromcoherence before the laser pulse's maximum to incoherence thereafter. Moreover,the time dependence of the spin-polarization components induced by spin-orbitcoupling differ significantly in Cu and Co: in Cu, we find long-periodoscillations with tiny rapid modulations, whereas in Co prominent rapidoscillations with long period ones are superimposed. The pronounced spatialdependencies of the signals underline the importance of inhomogeneities, inparticular magnetic/non-magnetic interfaces `act as source' for ultrafastspin-polarization effects. Our investigation provides detailed insight intoelectron dynamics during and shortly after a femtosecond laser excitation.

展开全部

图表提取

论文十问

参考文献

被引用

提问与回答

暂无人提供速读十问回答