Phase transitions and scale invariance in topological Anderson insulators

Fuente: arXiv
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Autori principali: Assunção, Bryan D., Ferreira, Gerson J., Lewenkopf, Caio H.
Natura: Preprint
Pubblicazione: 2024
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author Assunção, Bryan D.
Ferreira, Gerson J.
Lewenkopf, Caio H.
author_facet Assunção, Bryan D.
Ferreira, Gerson J.
Lewenkopf, Caio H.
contents We investigate disordered-driven transitions between trivial and topological insulator (TI) phases in two-dimensional (2D) systems. Our study primarily focuses on the BHZ model with Anderson disorder, while other standard 2DTI models exhibit equivalent features. The analysis is based on the local Chern marker (LCM), a local quantity that allows for the characterization of topological transitions in finite and disordered systems. Our simulations indicate that disorder-driven trivial to topological insulator transitions are nicely characterized by $\mathcal{C}_0$, the disorder averaged LCM near the central cell of the system. We show that $\mathcal{C}_0$ is characterized by a single-parameter scaling, namely, $\mathcal{C}_0(M, W, L) \equiv \mathcal{C}_0(z)$ with $z = [W^μ-W_c^μ(M)]L$, where $M$ is the Dirac mass, $W$ is the disorder strength and $L$ is the system size, while $W_c(M) \propto \sqrt{M}$ and $μ\approx 2$ stand for the critical disorder strength and critical exponent, respectively. Our numerical results are in agreement with a theoretical prediction based on a first-order Born approximation (1BA) analysis. These observations lead us to speculate that the universal scaling function we have found is rather general for amorphous and disorder-driven topological phase transitions.
format Preprint
id arxiv_https___arxiv_org_abs_2401_03028
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Phase transitions and scale invariance in topological Anderson insulators
Assunção, Bryan D.
Ferreira, Gerson J.
Lewenkopf, Caio H.
Disordered Systems and Neural Networks
Mesoscale and Nanoscale Physics
Materials Science
We investigate disordered-driven transitions between trivial and topological insulator (TI) phases in two-dimensional (2D) systems. Our study primarily focuses on the BHZ model with Anderson disorder, while other standard 2DTI models exhibit equivalent features. The analysis is based on the local Chern marker (LCM), a local quantity that allows for the characterization of topological transitions in finite and disordered systems. Our simulations indicate that disorder-driven trivial to topological insulator transitions are nicely characterized by $\mathcal{C}_0$, the disorder averaged LCM near the central cell of the system. We show that $\mathcal{C}_0$ is characterized by a single-parameter scaling, namely, $\mathcal{C}_0(M, W, L) \equiv \mathcal{C}_0(z)$ with $z = [W^μ-W_c^μ(M)]L$, where $M$ is the Dirac mass, $W$ is the disorder strength and $L$ is the system size, while $W_c(M) \propto \sqrt{M}$ and $μ\approx 2$ stand for the critical disorder strength and critical exponent, respectively. Our numerical results are in agreement with a theoretical prediction based on a first-order Born approximation (1BA) analysis. These observations lead us to speculate that the universal scaling function we have found is rather general for amorphous and disorder-driven topological phase transitions.
title Phase transitions and scale invariance in topological Anderson insulators
topic Disordered Systems and Neural Networks
Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2401.03028