Topological non-Hermitian origin of surface Maxwell waves

Area of Science:

• Physics
• Optics
• Condensed Matter Physics

Background:

• Maxwell electromagnetism describes light's wave properties.
• Surface electromagnetic waves at interfaces are crucial for plasmonics, metamaterials, and nano-photonics.
• These waves exist at interfaces between various optical media.

Purpose of the Study:

• To demonstrate the topological origin of surface Maxwell waves at interfaces between homogeneous isotropic media.
• To classify these topological properties using the helicity operator.
• To reveal the role of the helicity operator in determining the number of surface modes.

Main Methods:

• Applying bulk-boundary correspondence to analyze surface Maxwell waves.
• Utilizing the helicity operator for topological classification.
• Calculating a topological invariant based on the winding of the complex helicity spectrum.

Main Results:

• Surface Maxwell waves at interfaces between homogeneous isotropic media possess a topological origin.
• The topological classification is governed by a generically non-Hermitian helicity operator.
• A winding number invariant, derived from the helicity spectrum, quantifies the number of surface modes.

Conclusions:

• The study reveals a topological origin for surface Maxwell waves, linking them to bulk-boundary correspondence.
• The helicity operator, even when non-Hermitian, is key to topological classification.
• This work offers new insights into Maxwell electromagnetism, topological quantum states, non-Hermitian physics, and metamaterials.