Tunable Toroidal Response in a Reconfigurable Terahertz Metamaterial
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 09, 2021
- Source ID
- 10.1002/adom.202101215
Entities
People
- Chunxu Chen
- Kelson Kaj
- Richard D. Averitt
- Xiaoguang Zhao
- Xin Zhang
- Yuwei Huang
Organizations
- Army Research Office
- Boston University
- National Science Foundation
- University of California, San Diego