Investigating nanoplasmonics in an explicit time-dependent perspective is a natural choice when light pulses are used and may also reveal aspects that are hidden in a frequency-based picture. In the past, we proposed a method time domain-boundary element method (TD-BEM) to simulate the time dependent polarization of nanoparticles based on a boundary element method that is particularly suitable to interface with a quantum atomistic description of nearby molecules. So far, however, metal dielectric functions in TD-BEM have been modeled through analytic expressions, such as those of Debye and Drude–Lorentz, which cannot account for multiple electronic resonances. Our approach allows us to include in the TD-BEM framework also the description of metals with complicate dielectric function profiles in the frequency domain. Particularly, among all metals, gold is a challenging case due to the presence of many transition frequencies. We applied our methods to different metals (gold, silver, and the less commonly investigated rhodium) and different shaped nanoparticles (spheres, ellipsoids, and cubes), the approach has been tested comparing TD-BEM and frequency domain BEM absorption spectra, and it has been used to investigate the time-dependent field acting locally close to nanoparticle vertices.

中文翻译：

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通过具有通用介电函数的边界元方法描述纳米粒子中等离子体共振的实时动力学

当使用光脉冲时，以明确的时间相关角度研究纳米等离子体技术是一种自然的选择，并且还可能揭示基于频率的图片中隐藏的方面。过去，我们提出了一种时域边界元方法（TD-BEM），该方法基于边界元方法来模拟纳米粒子的时间依赖性极化，该方法特别适合与附近分子的量子原子描述相接。但是，到目前为止，TD-BEM中的金属介电功能已经通过解析表达式建模，例如Debye和Drude-Lorentz的解析表达式，它们不能解释多重电子共振。我们的方法使我们能够在TD-BEM框架中包括对在频域中具有复杂介电功能曲线的金属的描述。特别是在所有金属中 由于存在许多过渡频率，金是具有挑战性的情况。我们将我们的方法应用于不同的金属（金，银和较少研究的铑）和不同形状的纳米粒子（球形，椭圆形和立方体），该方法已通过比较TD-BEM和频域BEM吸收光谱进行了测试，已被用于研究局部作用于纳米粒子顶点附近的时间相关场。