Observation of a Topological Edge State Stabilized by Dissipation.

Area of Science:

• Condensed Matter Physics
• Topological Materials
• Photonics

Background:

• Topological band structures are typically associated with robust boundary states in closed systems.
• Topologically protected states can emerge in systems with trivial band structures when subjected to controlled losses.

Purpose of the Study:

• To investigate the dissipation-induced emergence of topological band structures in a non-Hermitian one-dimensional lattice.
• To experimentally realize and characterize topological edge states in plasmonic waveguide arrays.

Main Methods:

• Utilizing arrays of plasmonic waveguides with tailored dissipation to create a non-Hermitian lattice.
• Modulating dissipation and hopping parameters to tune the system's topological properties.
• Directly observing the topological edge state within the band gap.

Main Results:

• Direct evidence for a topological edge state located at the center of the band gap was obtained.
• Demonstrated the formation and breakdown of an interface state by tuning dissipation and hopping.
• Showcased the tunability of topological properties through engineered dissipation.

Conclusions:

• Dissipation can induce non-Hermitian topological band structures and protected edge states.
• Plasmonic waveguide arrays provide a viable platform for studying dissipation-induced topological phenomena.
• The observed interface states highlight the dynamic control over topological transitions.