Tunable Toroidal Response in a Reconfigurable Terahertz Metamaterial
Tunable Toroidal Response in a Reconfigurable Terahertz Metamaterial
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DOI：
10.1002/adom.202101215
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发表时间：
2021-09
影响因子：
9
通讯作者：
Chunxu Chen;Kelson J. Kaj;Yuwei Huang;Xiaoguang Zhao;R. Averitt;Xin Zhang
中科院分区：
文献类型：
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作者：
Chunxu Chen;Kelson J. Kaj;Yuwei Huang;Xiaoguang Zhao;R. Averitt;Xin Zhang
与传统的电多极子和磁多极子相比，动态环矩的存在近年来受到越来越多的关注。这是由于其新颖的电磁响应，包括动态非辐射电荷电流配置和非互惠相互作用。提出了可重构太赫兹超材料，其中人工环形超分子和传统的微机电系统双材料悬臂梁结构集成在同一单位单元内。通过由热致动修改弯曲角度，环形偶极子强度在平面外方向上增加了五个数量级，环形强度总体增加了近一个数量级。太赫兹时域光谱用于确定作为弯曲角度的函数的透射的演变。这使得使用多极分解的环形响应的数值确认与相位分析提供的额外确认。结果表明，使用双材料杠杆实现可调的环形力矩，在传感和下一代通信技术中具有潜在的应用。
Compared with the traditional electric and magnetic multipoles, the existence of a dynamic toroidal moment has received increasing interest in recent years. This is due to its novel electromagnetic response, including dynamic non‐radiating charge‐current configurations and non‐reciprocal interactions. Reconfigurable terahertz metamaterials where artificial toroidal metamolecules and traditional microelectromechanical systems bi‐material cantilever structures are integrated within the same unit cell are presented. Through modification of the bending angle by thermal actuation, the toroidal dipole intensity increases by five orders of magnitude in the out‐of‐plane direction with an overall increase in the toroidal intensity of nearly an order of magnitude. Terahertz time‐domain spectroscopy is used to determine the evolution of the transmission as a function of the bending angle. This enables numerical confirmation of the toroidal response using multipole decomposition with additional confirmation provided by phase analysis. The results demonstrate the use of bi‐material cantilevers to realize a tunable toroidal moment with potential applications in sensing and next‐generation communication technologies.