AI 中文总结
本研究针对太赫兹光谱中金属薄膜磁导率为1的常规假设，通过自洽反演方法分析10nm厚铝、铜薄膜的太赫兹时域光谱数据，发现Drude型薄膜存在显著偏离1的巨有效磁导率，揭示了其与薄膜电抗的关联及物理机制，修正了非磁性Drude薄膜的太赫兹电动力学表征假设。
AI 中文摘要
在太赫兹光谱研究中，金属薄膜的电磁响应通常通过假设相对磁导率为1来分析。本研究表明，该假设会在高导电薄膜的电动力学参数反演中引入显著偏差。研究采用太赫兹时域光谱技术，在透射和反射两种配置下对厚度为10 nm的铝膜和铜膜开展了研究。通过应用可独立确定复介电常数和磁导率的自洽反演方法，我们发现Drude型介电响应始终伴随着与1偏差极大的磁导率。这种偏差与薄膜的电抗阻抗存在本质关联，阐明了横向受限几何结构中光诱导的大屏蔽电流的产生机制。基于法拉第-诺依曼-楞次机制的唯象解释以及薄膜阻抗的集总元件模型，能够解释观测到的变化趋势。这些结果表明，在非磁性Drude薄膜中普遍采用的$\tildeμ=1$假设，可能会导致太赫兹频段的电动力学表征不完整或存在偏差。
英文摘要
The electromagnetic response of metallic films is commonly analyzed in terahertz spectroscopy by assuming unit relative magnetic permeability. In this work we show that this assumption introduces significant distortions in the electrodynamic retrieval of highly conductive films. Aluminum and copper films, 10 nm thick, were investigated by terahertz time-domain spectroscopy in both transmission and reflection configurations. By applying a self consistent retrieval method that independently determines the complex permittivity and permeability, we show that the Drude-type dielectric response is systematically accompanied by a permeability that strongly departs from unity. This deviation is intrinsically linked to the reactive impedance of the films, which clarifies the light induced onset of large screening currents within a transversally confined geometry. A phenomenological interpretation based on the Faraday Neumann Lenz mechanism and a lumped-element model of the film impedance accounts for the observed trends. These results indicate that the common assumption $\tildeμ=1$ in non-magnetic Drude films can lead to an incomplete or biased electrodynamic characterization in the terahertz regime.
Comments18 pages, 11 figures
