Electrically Controllable Molecularization of Terahertz Meta-Atoms

Area of Science:

• Metamaterials Science
• Terahertz (THz) Technology
• Nanoscale Engineering

Background:

• Active control of terahertz (THz) metamaterial properties is crucial for advanced applications.
• Current methods face challenges in tuning THz resonance frequency and phase shift.
• Existing approaches often struggle with significant transmission loss during tuning.

Purpose of the Study:

• To present a novel device design for extensive tuning of THz metamaterial properties.
• To introduce a strategy called 'molecularization' for controlling meta-atom electrical interconnections.
• To demonstrate voltage-controlled tuning of resonance frequency and phase shift in THz metamaterials.

Main Methods:

• Developed a device design utilizing graphene bridges between metallic unit structures.
• Implemented electrolyte gating to modulate the conductivity of graphene bridges.
• Employed a 'molecularization' strategy by varying the number of meta-atoms in unit metamolecules.

Main Results:

• Achieved scalable tuning of terahertz metamaterial resonance frequency based on the number of meta-atoms.
• Demonstrated delicate, voltage-controlled adjustment of the phase shift for transmitted THz waves.
• Maintained high transmission levels of the metamaterials during property modulation.

Conclusions:

• The molecularization strategy offers a new pathway for active control of THz metamaterials.
• This method provides precise tunability of both resonance frequency and phase shift.
• The design is scalable and maintains high transmission, paving the way for advanced THz devices.