Projected amorphous topological insulators
Abstract
We introduce projected amorphous topological insulators (PATIs) that despite containing only a fraction (x) of otherwise randomly selected {\it disconnected} sites of a parent crystal, feature a quantized global topological invariant ({\it strong} PATIs) when its effective Hamiltonian is constructed by integrating out the residual sites of the original lattice. Within the topological regime of the parent model, additionally, there exists a critical x below which such systems foster a {\it fragile} PATI that only supports quantized local topological marker on a small fraction of sites therein. Both strong and fragile PATIs accommodate in-gap modes near the boundary. The system also hosts a normal insulator in the entire trivial parameter regime of the lattice-based model for any x, devoid of gapless boundary modes, for which both global topological invariant and local topological marker vanish. We demonstrate these {\it possibly} generic outcomes by starting with a parent square lattice-based model for time-reversal symmetry breaking insulators. Then the strong-to-fragile PATI quantum phase transition, tunable via x, is characterized by the {\it mean} correlation length exponent ν∈ (1.00,1.46).
Related
- Nonlinearity-Induced Suppression of Dissipation in Bath-Coupled Floquet Topological Insulators
- Topological Boundary States and the Edge Chain in Semi-Infinite Two-Dimensional Insulators
- Anti-higher-order topological insulators
- Topological insulators on complex networks
- Collinear altermagnetism for 3D chiral higher-order topological insulators
BibTeX
@misc{panigrahi2026projected,
title = {{Projected amorphous topological insulators}},
author = {Archisman Panigrahi and Bitan Roy},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.30260},
eprint = {2609.30260},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.30260},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Projected amorphous topological insulators
AU - Archisman Panigrahi
AU - Bitan Roy
PY - 2026
DA - 2026/09/24
PB - arXiv
DO - 10.48550/arxiv.2609.30260
UR - https://arxiv.org/abs/2609.30260
AB - We introduce projected amorphous topological insulators (PATIs) that despite containing only a fraction (x) of otherwise randomly selected {\it disconnected} sites of a parent crystal, feature a quantized global topological invariant ({\it strong} PATIs) when its effective Hamiltonian is constructed by integrating out the residual sites of the original lattice. Within the topological regime of the parent model, additionally, there exists a critical x below which such systems foster a {\it fragile} PATI that only supports quantized local topological marker on a small fraction of sites therein. Both strong and fragile PATIs accommodate in-gap modes near the boundary. The system also hosts a normal insulator in the entire trivial parameter regime of the lattice-based model for any x, devoid of gapless boundary modes, for which both global topological invariant and local topological marker vanish. We demonstrate these {\it possibly} generic outcomes by starting with a parent square lattice-based model for time-reversal symmetry breaking insulators. Then the strong-to-fragile PATI quantum phase transition, tunable via x, is characterized by the {\it mean} correlation length exponent ν∈ (1.00,1.46).
ER -