Four-band effective square lattice model for Bernal-stacked bilayer graphene

Fuente: arXiv
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Main Authors: Chen, Szu-Chao, Mreńca-Kolasińska, Alina, Liu, Ming-Hao
Format: Preprint
Published: 2024
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author Chen, Szu-Chao
Mreńca-Kolasińska, Alina
Liu, Ming-Hao
author_facet Chen, Szu-Chao
Mreńca-Kolasińska, Alina
Liu, Ming-Hao
contents Bernal-stacked bilayer graphene (BLG) provides an ideal basis for gate-controlled, and free of etching, electronic devices. Theoretical modeling of realistic devices is an essential part of research, however, simulations of large-scale BLG devices continue to be extremely challenging. Micrometer-sized systems are predominantly beyond the reach of the commonly used atomistic tight-binding method, while other numerical approaches based on the two dimensional Dirac equation are not straightforward to conduct due to the fermion doubling problem. Here we present an approach based on the continuum model, unharmed by the fermion doubling. The discretization of the BLG continuum Hamiltonian leads to an effective four-band model, with both valleys built-in. We demonstrate its performance with realistic, large-scale systems, and obtain results consistent with experiments and with the tight-binding model, over a broad range of magnetic field.
format Preprint
id arxiv_https___arxiv_org_abs_2403_03155
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Four-band effective square lattice model for Bernal-stacked bilayer graphene
Chen, Szu-Chao
Mreńca-Kolasińska, Alina
Liu, Ming-Hao
Mesoscale and Nanoscale Physics
Bernal-stacked bilayer graphene (BLG) provides an ideal basis for gate-controlled, and free of etching, electronic devices. Theoretical modeling of realistic devices is an essential part of research, however, simulations of large-scale BLG devices continue to be extremely challenging. Micrometer-sized systems are predominantly beyond the reach of the commonly used atomistic tight-binding method, while other numerical approaches based on the two dimensional Dirac equation are not straightforward to conduct due to the fermion doubling problem. Here we present an approach based on the continuum model, unharmed by the fermion doubling. The discretization of the BLG continuum Hamiltonian leads to an effective four-band model, with both valleys built-in. We demonstrate its performance with realistic, large-scale systems, and obtain results consistent with experiments and with the tight-binding model, over a broad range of magnetic field.
title Four-band effective square lattice model for Bernal-stacked bilayer graphene
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2403.03155