This paper reviews recent progress in perfect absorbers of electromagnetic waves that utilize metamaterials (MMs). Various numerical techniques that are inevitable for the research on MMs, along with their pros and cons, are commented on and discussed. Abandoning the conventional periodic-boundary conditions is crucial for understanding the discrepancy between simulation and experiments for certain MMs. Broadband perfect absorption can be realized by using multiple resonances and/or multiple units with different sizes in a unit cell, or by utilizing bad Q-factors by incorporating the electrically resistive components, in addition to the ordinary metallic elements. The classical analogue of electromagnetically-induced transparency can be utilized to realize perfect absorption, by employing either structural asymmetry, or near-field interactions. Perspectives and suggestions for further study are discussed.

中文翻译：

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利用超材料的完美吸收体的最新进展

本文回顾了利用超材料 (MM) 的电磁波完美吸收器的最新进展。对MMs研究中不可避免的各种数值技术及其优缺点进行了评论和讨论。放弃传统的周期性边界条件对于理解某些 MM 的模拟和实验之间的差异至关重要。宽带完美吸收可以通过在一个单元中使用多个谐振和/或多个不同尺寸的单元来实现，或者通过在普通金属元件之外加入电阻元件来利用差的 Q 因子。通过采用结构不对称或近场相互作用，可以利用电磁感应透明的经典模拟来实现完美吸收。