Tunable Triple-Band Terahertz Perfect Absorber and Four-Input AND Gate Based on a Graphene Metamaterial

Area of Science:

• Metamaterials and Nanophotonics
• Terahertz (THz) Technology
• Plasmonics

Background:

• Perfect absorbers are crucial for THz applications.
• Graphene's tunable properties offer dynamic control in THz devices.
• Integrating multiple functionalities into single THz devices remains a challenge.

Purpose of the Study:

• To design and demonstrate a switchable, tunable, multi-peak terahertz absorber.
• To integrate logic gate and sensing capabilities within the absorber structure.
• To explore the potential of the device in THz communication and sensing.

Main Methods:

• Fabrication of a composite structure with graphene and double concentric metal rings on a gold substrate.
• Analysis of absorption spectra and electric field distributions to understand resonance mechanisms.
• Utilizing graphene's electrical tunability (Fermi level variation) for dynamic control.

Main Results:

• Achieved three high-absorption peaks (99.05%, 99.56%, 97.23%) in the far-infrared band.
• Demonstrated tunable absorption by varying the graphene Fermi level.
• Successfully embedded a four-input AND logic gate and achieved high refractive index sensitivity (30.1 THz/RIU and 62.5 THz/RIU).

Conclusions:

• The proposed structure offers a multifunctional platform for tunable absorption, logic operations, and sensing in the terahertz regime.
• The integration of these functionalities in a single device is a significant advancement for THz technology.
• The device shows promise for applications in terahertz communication, intelligent sensing, and reconfigurable systems.