We present experimental evidence of a spin voltage—a difference between the chemical potentials of the two spin directions—in a thin iron film based on spin- and time-resolved photoemission spectroscopy. This voltage is the driving force for a spin current during the ultrafast demagnetization of the sample. The observed magnitude is on the order of 50 mV, a value that is quite consistent with predictions based on particle conservation and persists for approximately 100 fs.

中文翻译：

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铁薄膜中飞秒自旋电压脉冲的检测

我们提供了基于自旋和时间分辨光发射光谱的铁薄膜中自旋电压（两个自旋方向的化学势之间的差异）的实验证据。该电压是样品超快退磁期间自旋电流的驱动力。观测到的幅度约为50 mV，该值与基于粒子守恒的预测非常一致，并持续约100 fs。