论文标题
辐射衰减速率和表面等离子体模式的频率转移的量子理论
Quantum Theory of Radiative Decay Rate and Frequency Shift of Surface Plasmon Modes
论文作者
论文摘要
在本文中，我们通过使用Hopfield方法来量化等离子体模式，在时间域中研究了任意形状的金属纳米颗粒中局部表面等离子体与光子之间的相互作用，在该方法中，电子振荡由和谐物质场线性地线性耦合到电磁辐射。等离子 - 光子耦合产生了衣服的等离子模式。我们发现，辐射不会引起不同准电压等离子模式的大小颗粒的显着耦合，直到等离子体波长，但会导致频移和模式的指数衰减。通过求解管理等离子创建和歼灭算子的期望值的方程，我们为衰减速率和等离子体模式的频率转移获得了新的封闭形式的全波表达式。它是非扰动的，仅取决于准电压等离子体模式的表面电荷分布。我们以与血浆波长相当的半径的纳米球体来验证MIE理论的表达。最终，我们研究了非典型形状的分离和相互作用的纳米颗粒中等离子体模式的衰减速率和频移，因为它们的尺寸增加到血浆波长。
In this paper we study, in the time domain, the interaction between localized surface plasmons and photons in arbitrarily shaped metal nanoparticles, by using the Hopfield approach to quantize the plasmon modes, where the electron oscillations are represented by a harmonic matter field linearly coupled to the electromagnetic radiation. The plasmon - photon coupling gives rise to dressed plasmon modes. We have found that the radiation does not induce a significant coupling among the different quasi-electrostatic plasmon modes for particles of size up to the plasma wavelength, but causes a frequency shift and an exponential decay in time of the modes. By solving the equations governing the expectation values of the plasmon creation and annihilation operators, we obtain a new closed-form full-wave expression for the decay rate and for the frequency shift of the plasmon modes. It is non-perturbative and it only depends on the surface charge distribution of the quasi-electrostatic plasmon modes. We validate the expression against the Mie theory for a nano-sphere of radius comparable to the plasma wavelength. Eventually, we investigate the decay rate and the frequency shift of the plasmon modes in isolated and interacting nanoparticle of non-canonical shape, as their size increases up to the plasma wavelength.
