Unique Berry phase in one-dimensional topological photonic systems

Area of Science:

• Condensed matter physics
• Photonics
• Topological materials

Background:

• Topological photonic systems are typically characterized using the typical Zak phase (TZP).
• The TZP's quantization depends on the choice of origin within the unit cell.
• This origin dependence can lead to ambiguities in determining topological properties.

Purpose of the Study:

• To introduce a new concept, the unique Berry phase (UBP), for identifying topological nature in 1D photonic systems.
• To address the limitations and ambiguities associated with the traditional TZP.
• To provide a more robust method for topological phase identification.

Main Methods:

• Development of the unique Berry phase (UBP) concept.
• Analysis of 1D topological photonic systems.
• Comparison of UBP with the typical Zak phase (TZP) under varying origin positions.

Main Results:

• The UBP provides a consistent topological invariant irrespective of the chosen origin.
• UBP avoids the quantization ambiguities inherent in the TZP.
• The UBP can accurately predict topological phase transitions in 1D photonic systems.

Conclusions:

• The unique Berry phase (UBP) is a superior topological invariant for 1D photonic systems compared to the TZP.
• UBP offers arbitrary origin selection, resolving ambiguities in topological characterization.
• This new phase provides a reliable tool for understanding and predicting topological phenomena in photonics.