Quantum Hall criticality in an amorphous Chern insulator

Fuente: arXiv
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Autori principali: Bera, Soumya, Dieplinger, Johannes, Nayak, Naba P
Natura: Preprint
Pubblicazione: 2024
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author Bera, Soumya
Dieplinger, Johannes
Nayak, Naba P
author_facet Bera, Soumya
Dieplinger, Johannes
Nayak, Naba P
contents We explore the critical properties of a topological transition in a two-dimensional, amorphous lattice with randomly distributed points. The model intrinsically breaks the time-reversal symmetry without an external magnetic field, akin to a Chern insulator. Here, the topological transition is induced by varying the density of lattice points or adjusting the mass parameter. Using the two-terminal conductance and multifractality of the wavefunction, we found that the topological transition belongs to the same universality class as the integer quantum Hall transition. Regardless of the approach to the critical point across the phase boundary, the localization length exponent remains within $ν\approx 2.55 - 2.61$. The irrelevant scaling exponent for both the observables is $y \approx 0.3(1)$, comparable to the values obtained using transfer matrix analysis in the Chalker-Coddigton network. Additionally, the investigation of the entire distribution function of the inverse participation ratio at the critical point shows possible deviations from the parabolic multifractal spectrum at the anomalous quantum Hall transition.
format Preprint
id arxiv_https___arxiv_org_abs_2401_11855
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Quantum Hall criticality in an amorphous Chern insulator
Bera, Soumya
Dieplinger, Johannes
Nayak, Naba P
Mesoscale and Nanoscale Physics
Disordered Systems and Neural Networks
Statistical Mechanics
We explore the critical properties of a topological transition in a two-dimensional, amorphous lattice with randomly distributed points. The model intrinsically breaks the time-reversal symmetry without an external magnetic field, akin to a Chern insulator. Here, the topological transition is induced by varying the density of lattice points or adjusting the mass parameter. Using the two-terminal conductance and multifractality of the wavefunction, we found that the topological transition belongs to the same universality class as the integer quantum Hall transition. Regardless of the approach to the critical point across the phase boundary, the localization length exponent remains within $ν\approx 2.55 - 2.61$. The irrelevant scaling exponent for both the observables is $y \approx 0.3(1)$, comparable to the values obtained using transfer matrix analysis in the Chalker-Coddigton network. Additionally, the investigation of the entire distribution function of the inverse participation ratio at the critical point shows possible deviations from the parabolic multifractal spectrum at the anomalous quantum Hall transition.
title Quantum Hall criticality in an amorphous Chern insulator
topic Mesoscale and Nanoscale Physics
Disordered Systems and Neural Networks
Statistical Mechanics
url https://arxiv.org/abs/2401.11855