Tricontrollable pixelated metasurface for absorbing terahertz radiation

Area of Science:

• Metamaterials and Nanophotonics
• Terahertz Technology
• Electromagnetic Wave Manipulation

Background:

• Controllable electromagnetic constitutive parameters are key to realizing advanced metasurfaces.
• Efficient absorption of terahertz radiation is crucial for various applications.

Purpose of the Study:

• To formulate and investigate a tricontrollable metasurface for efficient terahertz absorption.
• To explore the tunability of absorption characteristics via multiple control modalities.

Main Methods:

• A pixel-based approach using biperiodic assemblies of discrete pixels for meta-atoms.
• Patching pixels with indium antimonide (InSb) for thermal/magnetic control and graphene for electrical control.
• Utilizing a metal-backed silicon nitride substrate.

Main Results:

• Achieved peak absorptance exceeding 0.95 with a narrow bandwidth (< 0.7 THz) between 2-4 THz.
• Demonstrated thermal, magnetic, and electrical controllability of the maximum-absorptance frequency.
• Identified mechanical rotation as a fourth control modality due to lack of rotational invariance.

Conclusions:

• The developed pixelated metasurface offers highly efficient and tunable terahertz absorption.
• Multiple control modalities (thermal, magnetic, electrical, mechanical) provide versatile manipulation of absorption properties.
• This work paves the way for advanced terahertz devices with reconfigurable functionalities.