Transport properties in a two-dimensional Su-Schrieffer-Heeger model in Quantum Hall Regime

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Auteurs principaux: Gupta, Aruna, Gandhi, Shaina, Sarkar, Niladri, Bandyopadhyay, Jayendra N.
Format: Preprint
Publié: 2024
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author Gupta, Aruna
Gandhi, Shaina
Sarkar, Niladri
Bandyopadhyay, Jayendra N.
author_facet Gupta, Aruna
Gandhi, Shaina
Sarkar, Niladri
Bandyopadhyay, Jayendra N.
contents We investigate the transport properties of a two-dimensional Su-Schrieffer-Heeger (2D SSH) model in the quantum Hall regime using non-equilibrium Green's function formalism (NEGF). The device Hamiltonian, where the 2D SSH model serves as the channel, is constructed using a nearest-neighbor tight-binding model. The effect of an external perpendicular magnetic field is incorporated into the contacts via Peierls substitution. We observe a transition from a gapped phase to a flat band regime at zero energy by varying the magnetic field. This transition is characterized by the emergence of highly localized states in the bulk or edges, which we observe by calculating local density-of-states (LDOS). We analyze transport in the system along two directions ($x$ and $y$) via transmission measurements, indicating a magnetic field-induced transition from insulating to metallic phase. The study of the energy spectrum of the system shows the formation of Landau levels. Moreover, the quantum number of the non-degenerate and degenerate Landau levels (transmission modes) can be any integer or only an odd integer, depending on diagonal, inter-cell, and intra-cell hopping strengths. From the analysis of the transport properties along $y$-direction, we find that edge modes play a crucial role in facilitating ballistic transport.
format Preprint
id arxiv_https___arxiv_org_abs_2409_16839
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Transport properties in a two-dimensional Su-Schrieffer-Heeger model in Quantum Hall Regime
Gupta, Aruna
Gandhi, Shaina
Sarkar, Niladri
Bandyopadhyay, Jayendra N.
Mesoscale and Nanoscale Physics
Quantum Physics
We investigate the transport properties of a two-dimensional Su-Schrieffer-Heeger (2D SSH) model in the quantum Hall regime using non-equilibrium Green's function formalism (NEGF). The device Hamiltonian, where the 2D SSH model serves as the channel, is constructed using a nearest-neighbor tight-binding model. The effect of an external perpendicular magnetic field is incorporated into the contacts via Peierls substitution. We observe a transition from a gapped phase to a flat band regime at zero energy by varying the magnetic field. This transition is characterized by the emergence of highly localized states in the bulk or edges, which we observe by calculating local density-of-states (LDOS). We analyze transport in the system along two directions ($x$ and $y$) via transmission measurements, indicating a magnetic field-induced transition from insulating to metallic phase. The study of the energy spectrum of the system shows the formation of Landau levels. Moreover, the quantum number of the non-degenerate and degenerate Landau levels (transmission modes) can be any integer or only an odd integer, depending on diagonal, inter-cell, and intra-cell hopping strengths. From the analysis of the transport properties along $y$-direction, we find that edge modes play a crucial role in facilitating ballistic transport.
title Transport properties in a two-dimensional Su-Schrieffer-Heeger model in Quantum Hall Regime
topic Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2409.16839