Gaptronics: multilevel photonics applications spanning zero-nanometer limits

Area of Science:

• Physics
• Materials Science
• Nanotechnology

Background:

• Recent advances in nanofabrication enable metallic gap structures with sub-nanometer to zero-nanometer widths.
• These structures exhibit significant electromagnetic field confinement and enhancement.
• Quantum phenomena are observed at a macroscopic scale within these nanoscale gaps.

Purpose of the Study:

• To provide an overview of wafer-scale metallic gap structures approaching the zero-nanometer limit.
• To discuss theoretical descriptions of metallic gaps from sub-10 to zero-nanometer scales.
• To present fabrication methods and applications of these advanced metallic gap structures.

Main Methods:

• Theoretical modeling of metallic gaps at the sub-10 to zero-nanometer scale.
• Review of wafer-scale fabrication techniques for creating ultra-narrow metallic gaps.
• Analysis of experimental results demonstrating the properties and applications of these structures.

Main Results:

• Metallic gaps down to zero-nanometer width exhibit strong electromagnetic field confinement and enhancement.
• Quantum phenomena are integrated into macroscopic metallic gap systems.
• Wafer-scale fabrication methods for zero-nanometer gaps have been developed.

Conclusions:

• The development of metallic gaps down to the zero-nanometer limit diversifies their applications.
• The field of 'gaptronics' is emerging, with potential in photochemistry, quantum optics, and 5G/6G communications.
• Ultra-narrow metallic gaps offer broadband applicability from visible to microwave frequencies.