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Topological Corner Modes Induced by Dirac Vortices in Arbitrary Geometry.
Xiaoxiao Wu1, Yan Meng2, Yiran Hao2
1Faculties of Sciences and Engineering, The University of Hong Kong, Hong Kong, China.
Physical Review Letters
|June 21, 2021
Summary
We developed a new method to create topological corner modes (TCMs) in any shape, overcoming previous geometric limitations. This breakthrough enables flexible designs for topological circuits and other wave systems.
Area of Science:
- Condensed Matter Physics
- Topological Materials
- Wave Phenomena
Background:
- Higher-order topological phases exhibit topological corner modes (TCMs) at domain boundaries.
- Existing methods for realizing TCMs are constrained by specific lattice symmetries and limited geometries.
Purpose of the Study:
- To develop a general scheme for inducing TCMs in arbitrary geometries.
- To overcome the limitations of symmetry-dependent TCM realization.
- To enable new applications in topological quantum circuits and classical wave systems.
Main Methods:
- Utilizing Dirac vortices induced by aperiodic Kekulé modulations.
- Designing and observing TCMs in square and pentagonal domains on triangular lattices.
- Demonstrating flexibility in controlling the number and position of TCMs.
Main Results:
- Successfully induced and experimentally observed TCMs in geometries not compatible with traditional lattice symmetries.
- Showcased TCMs in square and pentagonal domains, independent of lattice orientation.
- Established a versatile method for arbitrary placement and quantity of TCMs.
Conclusions:
- The proposed scheme provides a general route to realize TCMs in arbitrary geometries.
- This advancement significantly broadens the applicability of TCMs in topological circuits and other classical wave systems.
- The findings highlight the potential of aperiodic modulations in topological physics.
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