Assumpcao Daniel R, Siddique Radwanul Hasan, Choo Hyuck
Opt Express. 2021 Nov 22;29(24):39801-39810. doi: 10.1364/OE.443340.
Landau damping has previously been shown to be the dominant nonlocal effect in sub-10nm plasmonic nanostructures, although its effects on the performance of plasmonic nanocavities are still poorly understood. In this work, the effects of Landau damping in sub-10-nm planar plasmonic nanocavities are analyzed theoretically, and it is shown that while Landau damping does not affect the confinement of the cavity modes, it decreases the quality factor 10-fold due to the introduction of extra loss for sub-10nm gap sizes. As compared to purely classical models, this results in a suppression in the Purcell factor by 10 fold, the spontaneous emission rate by almost two orders of magnitude, and the required oscillator strength to achieve strong light-matter coupling by two orders of magnitude as the gap is reduced to ∼0.5nm. Therefore, it is crucial to consider Landau damping in plasmonic-nanocavity design because it breaks the classical norm of achieving higher light-matter interaction strength in sub-10-nm gap-plasmon nanocavities.
此前已表明，朗道阻尼是亚10纳米等离子体纳米结构中主要的非局部效应，不过其对等离激元纳米腔性能的影响仍鲜为人知。在这项工作中，从理论上分析了亚10纳米平面等离激元纳米腔中朗道阻尼的影响，结果表明，虽然朗道阻尼不影响腔模的限制，但由于亚10纳米间隙尺寸引入了额外损耗，它会使品质因数降低10倍。与纯经典模型相比，随着间隙减小到约0.5纳米，这会导致珀塞尔因子降低10倍，自发发射率降低近两个数量级，以及实现强光与物质耦合所需的振子强度降低两个数量级。因此，在等离激元纳米腔设计中考虑朗道阻尼至关重要，因为它打破了在亚10纳米间隙等离激元纳米腔中实现更高光与物质相互作用强度的经典准则。
