Switching between topological edge states in plasmonic systems using phase-change materials

Area of Science:

• Photonics
• Condensed Matter Physics
• Materials Science

Background:

• Topological edge states (TESs) offer robust transport properties.
• Non-Hermitian systems exhibit unique phenomena not found in their Hermitian counterparts.
• Phase-change materials provide dynamic control over optical properties.

Purpose of the Study:

• To realize dynamic switching between right and left topological edge states (TESs).
• To utilize the phase-change material Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) for reconfigurable topological photonic devices.
• To investigate non-Hermitian plasmonic waveguide-cavity structures based on the Aubry-Andre-Harper model.

Main Methods:

• Designing non-Hermitian plasmonic waveguide-cavity structures.
• Employing the Aubry-Andre-Harper model for theoretical analysis.
• Utilizing Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) as a phase-change material to tune optical properties.

Main Results:

• Demonstrated switching between right and left TESs at the same frequency.
• Showcased that phase transitions in GST shift the dispersion relation.
• Achieved reconfigurable topological states by switching GST between crystalline and amorphous phases.

Conclusions:

• Successfully realized reconfigurable topological edge states using phase-change materials.
• The proposed structures are promising for compact and tunable topological photonic devices.
• This work opens avenues for advanced optical functionalities in reconfigurable topological photonics.