We investigate the ultrafast nonlinear response of silver upon excitation by infrared electromagnetic radiation pulses with a duration of a few femtoseconds. By adopting the Landau weak coupling approach to account for electron–electron and electron–phonon collisions, we solve the Boltzmann equation through the method of moments obtaining a novel set of hydrodynamical equations describing the ultrafast nonlinear dynamics of electrons in silver. While the novel hydrodynamical model that was obtained reduces to the Drude model for small intensities of the driving field, it predicts that absorption saturates for large but experimentally attainable peak intensities of the order of GW cm⁻². Our results are important for absorption mitigation in plasmonic devices, with potential impact for low-loss plasmonic waveguides and interconnects.

中文翻译：

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超快电磁场驱动的银的失衡电子动力学–一种新颖的流体动力学方法

我们研究了银的超快非线性响应，其红外红外辐射脉冲的激发时间为几飞秒。通过采用Landau弱耦合方法解决电子-电子和电子-声子的碰撞，我们通过矩量法求解了玻尔兹曼方程，获得了描述银中电子超快非线性动力学的一组新颖的流体动力学方程。尽管对于驱动场的小强度，获得的新型流体动力学模型简化为Drude模型，但它预测，对于大的，但实验上可达到的GW cm ^-2的峰值强度，吸收达到饱和。。我们的结果对于减轻等离激元器件中的吸收非常重要，对低损耗的等离激元波导和互连具有潜在的影响。