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Updated: May 20, 2025
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Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
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Observation of Nonlinear Topological Corner States Originating from Different Spectral Charges
Victor O Kompanets1, Suge Feng2, Yiqi Zhang2
1Institute of Spectroscopy, Russian Academy of Sciences, Moscow, Troitsk, 108840, Russia.
Advanced Materials (Deerfield Beach, Fla.)
|May 19, 2025
Summary
Researchers demonstrate a novel 2D higher-order topological insulator (HOTI) using a Kekulé lattice. This new material exhibits unique topological corner states and stable nonlinear states, expanding the HOTI classification.
Area of Science:
- Condensed Matter Physics
- Topological Materials Science
Background:
- Higher-order topological insulators (HOTIs) host topological edge states with reduced dimensionality.
- Existing HOTIs require specific geometries where lattice and edge symmetries match.
Purpose of the Study:
- To experimentally demonstrate a new type of 2D HOTI with mismatched lattice and edge symmetries.
- To explore the topological corner states and nonlinear phenomena in this novel HOTI.
Main Methods:
- Fabrication of a 2D HOTI on a Kekulé-patterned lattice using fs-laser writing.
- Experimental observation of topological corner states, including those with spectral charge 5/6.
- Investigation of nonlinear phenomena, observing stable hybrid nonlinear corner states.
Main Results:
- A novel 2D HOTI was realized with a Kekulé lattice, exhibiting hybrid boundaries.
- All three possible types of topological corner states were observed, including a unique 5/6 spectral charge state.
- Stable nonlinear corner states were generated from linear topological states in a nonlinear dielectric.
Conclusions:
- This work introduces a new class of HOTIs with distinct symmetry properties.
- The findings pave the way for observing topological states with novel internal structures and symmetries.
- The observation of nonlinear topological states opens avenues for topological photonics and material science applications.
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