论文标题
通过Au/Fe/MgO（001）中的超快电子动力学（通过AU和Fe选择性抽水）在时间分辨的两光子光发射光谱中分析：相邻金属层的激发分离
Ultrafast electron dynamics in Au/Fe/MgO(001) analyzed by Au- and Fe-selective pumping in time-resolved two-photon photoemission spectroscopy: Separation of excitations in adjacent metallic layers
论文作者
论文摘要
通过飞秒，时间分辨的两光子光电发射光谱（2PPE）的外在au/fe/fe/mgo（001）分析异质结构中光激发的热电子的转运。我们比较了在光泵送Fe或au时2PPE强度的时间演变，而探测发生在AU表面上。在FE侧抽水的情况下，假设在Fe和Au层中独立放松，我们通过分析异质结构中观察到的有效电子寿命的AU层厚度依赖性来确定这些单个层中的热电子松弛时间。我们还表明，由于空间分布的光激发密度，这种系统分析对于AU端泵送的情况失败，这随着AU层的厚度而变化。这项工作扩展了先前的研究[Beyazit等，物理学。莱特牧师。 125，076803（2020）]通过新数据，导致确定的寿命中的误差线减少，并且在Au-Thickentes依赖性数据分析中通过非线性项，这有助于相似的Fe和Au膜厚度。
The transport of optically excited, hot electrons in heterostructures is analyzed by femtosecond, time-resolved two-photon photoelectron emission spectroscopy (2PPE) for epitaxial Au/Fe/MgO(001). We compare the temporal evolution of the 2PPE intensity upon optically pumping Fe or Au, while the probing occurs on the Au surface. In the case of Fe-side pumping, assuming independent relaxation in the Fe and Au layers, we determine the hot electron relaxation times in these individual layers by an analysis of the Au layer thickness dependence of the observed, effective electron lifetimes in the heterostructure. We show in addition that such a systematic analysis fails for the case of Au-side pumping due to the spatially distributed optical excitation density, which varies with the Au layer thickness. This work extends a previous study [Beyazit et al., Phys. Rev. Lett. 125, 076803 (2020)] by new data leading to reduced error bars in the determined lifetimes and by a non-linear term in the Au-thickness dependent data analysis which contributes for similar Fe and Au film thicknesses.
