Chen Hou-Tong
Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
Opt Express. 2012 Mar 26;20(7):7165-72. doi: 10.1364/OE.20.007165.
The impedance matching to free space in metamaterial perfect absorbers has been believed to involve and rely on magnetic resonant response, with direct evidence provided by the anti-parallel surface currents in the metal structures. Here I present a different theoretical interpretation based on interference, which shows that the two layers of metal structures in metamaterial absorbers are linked only by multiple reflections with negligible near-field interactions or magnetic resonances. This is further supported by the out-of-phase surface currents derived at the interfaces of resonator array and ground plane through multiple reflections and superpositions. The theory developed here explains all features observed in narrowband metamaterial absorbers and therefore provides a profound understanding of the underlying physics.
超材料完美吸收体中与自由空间的阻抗匹配一直被认为涉及并依赖于磁共振响应，金属结构中反平行表面电流提供了直接证据。在此，我基于干涉提出了一种不同的理论解释，该解释表明超材料吸收体中的两层金属结构仅通过多次反射相连，近场相互作用或磁共振可忽略不计。通过多次反射和叠加在谐振器阵列与接地平面界面处导出的异相表面电流进一步支持了这一点。这里发展的理论解释了在窄带超材料吸收体中观察到的所有特征，因此提供了对其潜在物理原理的深刻理解。
