Local Chern Marker for Periodic Systems

Fuente: arXiv
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Main Authors: Baù, Nicolas, Marrazzo, Antimo
Format: Preprint
Published: 2023
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author Baù, Nicolas
Marrazzo, Antimo
author_facet Baù, Nicolas
Marrazzo, Antimo
contents Topological invariants are global properties of the ground-state wave function, typically defined as winding numbers in reciprocal space. Over the years, a number of topological markers in real space have been introduced, allowing to map topological order in heterogeneous crystalline and disordered systems. Notably, even if these formulations can be expressed in terms of lattice-periodic quantities, they can actually be deployed in open boundary conditions only, as in practice they require computing the position operator $\mathbf{r}$ in a form that is ill-defined in periodic boundary conditions. Here we derive a local Chern marker for infinite two-dimensional systems with periodic boundary conditions in the large supercell limit, where the electronic structure is sampled with one single point in reciprocal space. We validate our approach with tight-binding numerical simulations on the Haldane model, including trivial/topological superlattices made of pristine and disordered Chern insulators. The strategy introduced here is very general and could be applied to other topological invariants and quantum-geometrical quantities in any dimension.
format Preprint
id arxiv_https___arxiv_org_abs_2310_15783
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Local Chern Marker for Periodic Systems
Baù, Nicolas
Marrazzo, Antimo
Mesoscale and Nanoscale Physics
Topological invariants are global properties of the ground-state wave function, typically defined as winding numbers in reciprocal space. Over the years, a number of topological markers in real space have been introduced, allowing to map topological order in heterogeneous crystalline and disordered systems. Notably, even if these formulations can be expressed in terms of lattice-periodic quantities, they can actually be deployed in open boundary conditions only, as in practice they require computing the position operator $\mathbf{r}$ in a form that is ill-defined in periodic boundary conditions. Here we derive a local Chern marker for infinite two-dimensional systems with periodic boundary conditions in the large supercell limit, where the electronic structure is sampled with one single point in reciprocal space. We validate our approach with tight-binding numerical simulations on the Haldane model, including trivial/topological superlattices made of pristine and disordered Chern insulators. The strategy introduced here is very general and could be applied to other topological invariants and quantum-geometrical quantities in any dimension.
title Local Chern Marker for Periodic Systems
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2310.15783