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Higher-Order Topological Insulators in Quasicrystals
Rui Chen1, Chui-Zhen Chen2, Jin-Hua Gao3
1Department of Physics, Hubei University, Wuhan 430062, China.
Physical Review Letters
|February 8, 2020
Summary
Higher-order topological insulators (HOTIs) are now achievable in quasicrystals, not just crystalline materials. This research introduces novel quasicrystalline topological insulators and a method for their experimental detection.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Physics
Background:
- Higher-order topological insulators (HOTIs) are typically studied in crystalline materials.
- Understanding HOTIs in non-periodic systems like quasicrystals remains an open challenge.
Purpose of the Study:
- To propose and investigate the realization of higher-order topological insulators (HOTIs) in quasicrystalline lattices (QLs).
- To explore two distinct types of second-order topological insulators (SOTIs) in quasicrystals: one gapped by a Wilson mass term and the quasicrystalline quadrupole insulator (QI).
- To identify unusual features of corner states (CSs) in these quasicrystalline SOTIs and propose an experimental detection method.
Main Methods:
- Theoretical construction of SOTIs on QLs with different tiling patterns.
- Utilizing a Wilson mass term to modify edge states of quantum spin Hall insulators on QLs.
- Designing an electrical circuit to simulate the quasicrystalline QI for experimental verification.
Main Results:
- Demonstrated the feasibility of realizing two types of SOTIs in quasicrystals.
- Revealed unique characteristics of corner states in these quasicrystalline systems.
- Showed that quasicrystalline QIs can be simulated in electrical circuits, with corner states detectable via impedance resonance.
Conclusions:
- Extends the paradigm of HOTIs beyond crystalline structures into the realm of quasicrystals.
- Provides a practical experimental pathway for identifying topological properties in quasicrystals.
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