Real-space approach for the Euler class and fragile topology in quasicrystals and amorphous lattices
Dexin Li, Citian Wang, Huaqing Huang
SciPost Phys. 17, 086 (2024) · published 20 September 2024
- doi: 10.21468/SciPostPhys.17.3.086
- Submissions/Reports
Abstract
We propose a real-space formalism of the topological Euler class, which characterizes the fragile topology of two-dimensional systems with real wave functions. This real-space description is characterized by local Euler markers whose macroscopic average coincides with the Euler number, and it applies equally well to periodic and open boundary conditions for both crystals and noncrystalline systems. We validate this by diagnosing topological phase transitions in clean and disordered crystalline systems with the reality endowed by the space-time inversion symmetry $\mathcal{I}_{ST}$. Furthermore, we demonstrated the topological Euler phases in quasicrystals and even in amorphous lattices lacking any spatial symmetries. Our work not only provides a local characterization of the fragile topology but also significantly extends its territory beyond $\mathcal{I}_{ST}$-symmetric crystalline materials.
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Dexin Li,
- 1 Citian Wang,
- 1 2 Huaqing Huang
- National Key Research and Development Program of China (through Organization: Ministry of Science and Technology of the People's Republic of China [MOST])
- National Natural Science Foundation of China [NSFC]
- 北京大学 / Peking University [PKU]