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Updated: Dec 13, 2025
08:01
Spectral and Angle-Resolved Magneto-Optical Characterization of Photonic Nanostructures
Published on: November 21, 2019
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Higher-order quantum spin Hall effect in a photonic crystal
Biye Xie1,2, Guangxu Su1,3, Hong-Fei Wang1,2
1National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China.
Nature Communications
|July 30, 2020
Summary
Researchers demonstrate a higher-order quantum spin Hall effect in photonic crystals. This allows for directional photon localization at corners, enabling new topological photonic devices.
Area of Science:
- Topological photonics
- Condensed matter physics
- Quantum mechanics
Background:
- The quantum spin Hall effect (QSHE) enables topologically protected wave manipulation but is limited to lower-dimensional boundaries.
- Higher-order topological phenomena extend topological states to higher codimensions, including hinges and corners.
Purpose of the Study:
- To demonstrate a higher-order quantum spin Hall effect in a two-dimensional photonic crystal.
- To explore novel topological states beyond conventional bulk-boundary correspondence.
Main Methods:
- Fabrication and characterization of a two-dimensional photonic crystal.
- Utilizing pseudospin-pseudospin coupling and higher-order band topology.
- Observation of pseudospin-momentum-locked edge waves.
Main Results:
- Demonstrated a higher-order quantum spin Hall effect in a photonic crystal.
- Achieved directional photon localization at corners with opposite pseudospin polarizations.
- Observed edge waves exhibiting pseudospin-momentum locking.
Conclusions:
- The study presents a higher-order QSHE in photonics, enabling corner-localized states.
- This work provides a new pathway for transporting and trapping spinful waves.
- Potential applications include spinful topological lasers and chiral quantum emitters.
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