Electron emission induced by surface plasmon polaritons (SPPs) or simply surface plasmons excited by high-intensity femtosecond laser irradiation of an ordered Au surface has been studied by time-of-flight (TOF) analysis of the emitted electrons. Significant differences have been found compared to the same analysis of smooth surfaces. The SPP field enhancement has been significantly increased in hot spots which have the same periodicity as the surface. In addition to the increased field enhancement, periodic narrow peaks have been detected in the TOF spectrum. In the laser intensity range, where the high-energy peak is present, some of (also periodic in time) less frequent narrow peaks are about twice as large as the remaining ones, indicating the detection of two electrons (Cooper pairs) at about the same time, namely within the resolution of the TOF spectrometer.

中文翻译：

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室温下有序金膜中表面等离子体辅助库珀对的形成

通过发射电子的飞行时间（TOF）分析，研究了由表面等离激元极化子（SPPs）或简单地由高强度飞秒激光辐照有序Au表面激发的表面等离激元引起的电子发射。与光滑表面的相同分析相比，发现了显着差异。在与表面具有相同周期性的热点中，SPP场增强得到了显着提高。除了增强的场增强之外，还已经在TOF光谱中检测到周期性的窄峰。在存在高能峰的激光强度范围内，一些频率较低的窄峰（在时间上也是周期性的）大约是其余峰的两倍，这表明在大约0℃处检测到两个电子（库珀对）。同时，