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Abstract：
Dielectric screening plays a vital role in determining physical properties at the nanoscale and affects our ability to detect and characterize nanomaterials using optical techniques. We study how dielectric screening changes electromagnetic fields and many-body effects in nanostructures encapsulated inside carbon nanotubes. First, we show that metallic outer walls reduce the scattering intensity of the inner tube by 2 orders of magnitude compared to that of air-suspended inner tubes, in line with our local field calculations. Second, we find that the dielectric shift of the optical transition energies in the inner walls is greater when the outer tube is metallic than when it is semiconducting. The magnitude of the shift suggests that the excitons in small-diameter inner metallic tubes are thermally dissociated at room temperature if the outer tube is also metallic, and in essence, we observe band-to-band transitions in thin metallic double-walled nanotubes.
摘要：
介电筛选在确定纳米级的物理性质中起着至关重要的作用，并影响我们使用光学技术检测和表征纳米材料的能力。我们研究了介电屏蔽如何改变碳纳米管内部封装的纳米结构中的电磁场和多体效应。首先,我们表明，与空气悬浮内管相比，金属外壁使内管的散射强度降低了2个数量级，符合我们当地的现场计算。第二,我们发现，当外管是金属时，内壁中光学跃迁能的介电位移大于半导电时。位移的大小表明，如果外管也是金属的，则小直径内金属管中的激子在室温下会热解离，从本质上讲，我们观察到薄金属双壁纳米管的带间跃迁。
