Fine structure constant and quantized optical transparency of plasmonic nanoarrays

Area of Science:

• Plasmonic Nanooptics
• Quantum Optics
• Condensed Matter Physics

Background:

• Optics has historically been crucial for understanding quantum mechanics through phenomena like blackbody radiation and the photoelectric effect.
• Universality in physical constants, such as the fine structure constant, was previously observed mainly in superconductivity (quantized resistance and flux quanta).
• The transparency of suspended graphene was unexpectedly found to be determined solely by the fine structure constant.

Purpose of the Study:

• To describe and investigate a novel plasmonic system exhibiting optical transparency determined by the fine structure constant.
• To explore the potential for universal dynamic conductance in plasmonic nanooptics.

Main Methods:

• Fabrication of a regular array of gold nanoparticles on a thin metallic sublayer.
• Characterization of the relative optical transparency of the plasmonic system in the near-infrared spectrum.
• Analysis of the relationship between optical transparency and quantized contact resistance.

Main Results:

• Demonstrated a plasmonic system where relative optical transparency is solely determined by the fine structure constant.
• Observed quantized transparency in the near-infrared region.
• Attributed the quantized transparency to quantized contact resistance between gold nanoparticles and the metallic sublayer.

Conclusions:

• The study establishes a plasmonic system exhibiting universal optical transparency, analogous to phenomena in superconductivity.
• Quantized contact resistance plays a key role in determining the optical properties of the plasmonic nanostructure.
• These findings open new avenues for exploring universal dynamic conductance in nano-scale optical systems.