On-Chip Non-Volatile Reconfigurable Phase Change Topological Photonics

Area of Science:

• Photonics
• Materials Science
• Condensed Matter Physics

Background:

• Terahertz (THz) topological photonic devices offer high capacity and reconfigurability for data systems.
• Current THz devices require continuous power due to volatile tuning mechanisms.

Purpose of the Study:

• To demonstrate a nonvolatile, programmable THz topological silicon chip.
• To enable persistent and efficient functionality without constant power input.

Main Methods:

• Integration of a waveguide-cavity coupled system with the phase-change material Ge₂Sb₂Te₅ (GST).
• Tuning of GST intermediate phase states (amorphous to crystalline) for non-volatile reconfiguration.
• Phototunable, volatile modulation for controlled resetting of cavity coupling states.

Main Results:

• Achieved stable, non-volatile reconfiguration of the topological cavity across different coupling states.
• Demonstrated multi-level modulation of resonance transmission with a 70 dB modulation depth.
• Enabled precise control over resonance modes and dynamic tuning of critical coupling.

Conclusions:

• The first nonvolatile, programmable THz topological integrated chip was demonstrated.
• This advancement paves the way for integrating phase-change materials into silicon topological chips.
• Enables flexible control over resonance modes for applications like interconnects, modulators, and logic circuits.