arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2001.11926physics.opticsquant-ph
收藏

表面等离子体模辐射衰减率和频移的量子理论

Quantum Theory of Radiative Decay Rate and Frequency Shift of Surface Plasmon Modes

Carlo Forestiere, Giovanni Miano, Mariano Pascale, Roberto Tricarico

摘要:

在本文中,我们研究,在时域内,局域表面等离子体和光子之间的相互作用,在任意形状的金属纳米粒子,通过使用Hopfield方法来描述的等离子体模式,其中的电子振荡表示的谐波物质场线性耦合到电磁辐射。等离子体-光子耦合产生修饰等离子体模。我们已经发现,辐射不诱导不同的准静电等离子体激元模式之间的显着耦合的粒子的大小达到等离子体波长,但会导致频率偏移和指数衰减的模式的时间。通过求解等离子体激元产生和湮灭算符的期望值方程,我们得到了一个新的封闭形式的衰减率和等离子体激元模式的频移的全波表达式。它是非微扰的,它只依赖于准静电等离子体激元模式的表面电荷分布。我们验证了米氏理论的纳米球的半径相当于等离子体波长的表达。最后,我们调查的衰减率和频率偏移的等离子体振子模式在孤立和相互作用的纳米粒子的非正则形状,因为它们的大小增加到等离子体波长。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑