Topologically Protected Edge State in Two-Dimensional Su-Schrieffer-Heeger Circuit

Area of Science:

• Condensed Matter Physics
• Electrical Engineering
• Topological Materials

Background:

• Topological circuits are a nascent field offering accessible platforms for exploring topological physics.
• Potential applications and phenomena within topological circuits remain largely undiscovered.

Purpose of the Study:

• To design and experimentally demonstrate a topologically nontrivial band structure in an RF circuit.
• To investigate the associated topologically protected edge states and their robustness.

Main Methods:

• An RF circuit was constructed using grounded capacitors and alternating inductors, analogous to the Su-Schrieffer-Heeger model.
• Circuit parameters were tuned to control the topological invariant (Zak phase) and band gap width.
• Experimental results were compared with simulation data.

Main Results:

• A topologically nontrivial band structure with protected edge states was successfully demonstrated.
• The edge states exhibited strong localization at the circuit boundaries.
• The system showed remarkable robustness against various defects.

Conclusions:

• The experimental demonstration provides a flexible platform for studying topological physics in circuits.
• This work highlights the potential for developing robust electronic circuits with tunable topological properties.