Chiral surface waves on hyperbolic-gyromagnetic metamaterials.

Area of Science:

• Condensed matter physics
• Electromagnetism
• Materials science

Background:

• Metamaterials offer unique electromagnetic properties not found in natural materials.
• Hyperbolic and gyromagnetic materials exhibit distinct wave propagation characteristics.
• Surface waves can confine and guide electromagnetic energy at interfaces.

Purpose of the Study:

• To investigate the existence and properties of surface waves at the boundary of hyperbolic-gyromagnetic metamaterials.
• To analytically formulate these surface waves and understand their chiral behavior.
• To explore the topological features and robustness of these waves.

Main Methods:

• Analytical formulation of surface waves using eigenfields.
• Characterization of wave properties, including polarization and propagation direction.
• Topological characterization using Berry phases.
• Numerical or experimental demonstration of wave propagation and disorder immunity.

Main Results:

• Surface waves exist in the spatial gap between elliptically polarized bulk modes.
• These surface waves are chiral, propagating unidirectionally and reversing direction with the gyrotropic parameter.
• Topological features, linked to Berry phases, confirm bulk-edge correspondence.
• Demonstrated unidirectionality and immunity to disorder through wave propagation simulations.

Conclusions:

• Hyperbolic-gyromagnetic metamaterials support chiral surface waves with unique topological properties.
• The observed bulk-edge correspondence highlights the topological nature of these waves.
• Chiral surface waves exhibit robustness against disorder, making them promising for waveguiding applications.