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Hofstadter butterflies in magnetically modulated graphene bilayer : An algebraic approach

Arora, Manisha ; Sachdeva, Rashi LU orcid and Ghosh, Sankalpa (2022) In Physica E: Low-Dimensional Systems and Nanostructures 142.
Abstract

It has been shown that Bernal stacked bilayer graphene (BLG) in a uniform magnetic field demonstrates integer quantum Hall effect with a zero Landau-level anomaly (Novoselov et al., 2006). In this article we consider such system in a two dimensional periodic magnetic modulation with square lattice symmetry. It is shown algebraically that the resulting Hofstadter spectrum can be expressed in terms of the corresponding spectrum of monolayer graphene in a similar magnetic modulation. In the weak-field limit, using the tight-binding model, we also derive the Harper–Hofstadter equation for such BLG system in a periodic magnetic modulation. We further demonstrate the topological quantisation of Hall conductivity in such system and point out... (More)

It has been shown that Bernal stacked bilayer graphene (BLG) in a uniform magnetic field demonstrates integer quantum Hall effect with a zero Landau-level anomaly (Novoselov et al., 2006). In this article we consider such system in a two dimensional periodic magnetic modulation with square lattice symmetry. It is shown algebraically that the resulting Hofstadter spectrum can be expressed in terms of the corresponding spectrum of monolayer graphene in a similar magnetic modulation. In the weak-field limit, using the tight-binding model, we also derive the Harper–Hofstadter equation for such BLG system in a periodic magnetic modulation. We further demonstrate the topological quantisation of Hall conductivity in such system and point out that the quantised Hall plateaus are equally spaced for all quantum numbers for the quantised Hall conductivity.

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Contribution to journal
publication status
published
subject
keywords
Bilayer graphene, Hofstadter butterfly, Magnetic modulation, Topological quantisation: Magnetic translation symmetry
in
Physica E: Low-Dimensional Systems and Nanostructures
volume
142
article number
115311
publisher
Elsevier
external identifiers
  • scopus:85131088193
ISSN
1386-9477
DOI
10.1016/j.physe.2022.115311
language
English
LU publication?
yes
id
c9746684-69d9-4c31-bc29-5b1e922a0b5e
date added to LUP
2022-12-28 10:14:44
date last changed
2023-11-21 14:44:35
@article{c9746684-69d9-4c31-bc29-5b1e922a0b5e,
  abstract     = {{<p>It has been shown that Bernal stacked bilayer graphene (BLG) in a uniform magnetic field demonstrates integer quantum Hall effect with a zero Landau-level anomaly (Novoselov et al., 2006). In this article we consider such system in a two dimensional periodic magnetic modulation with square lattice symmetry. It is shown algebraically that the resulting Hofstadter spectrum can be expressed in terms of the corresponding spectrum of monolayer graphene in a similar magnetic modulation. In the weak-field limit, using the tight-binding model, we also derive the Harper–Hofstadter equation for such BLG system in a periodic magnetic modulation. We further demonstrate the topological quantisation of Hall conductivity in such system and point out that the quantised Hall plateaus are equally spaced for all quantum numbers for the quantised Hall conductivity.</p>}},
  author       = {{Arora, Manisha and Sachdeva, Rashi and Ghosh, Sankalpa}},
  issn         = {{1386-9477}},
  keywords     = {{Bilayer graphene; Hofstadter butterfly; Magnetic modulation; Topological quantisation: Magnetic translation symmetry}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Physica E: Low-Dimensional Systems and Nanostructures}},
  title        = {{Hofstadter butterflies in magnetically modulated graphene bilayer : An algebraic approach}},
  url          = {{http://dx.doi.org/10.1016/j.physe.2022.115311}},
  doi          = {{10.1016/j.physe.2022.115311}},
  volume       = {{142}},
  year         = {{2022}},
}