Dirac-Rashba fermions and quantum valley Hall insulators in graphene-based 2D heterostructures

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Hauptverfasser: Yu, Bo-Wen, Liu, Bang-Gui
Format: Preprint
Veröffentlicht: 2024
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author Yu, Bo-Wen
Liu, Bang-Gui
author_facet Yu, Bo-Wen
Liu, Bang-Gui
contents It is highly desirable to modify and improve the Dirac electron system of graphene for novel electronic properties and promising applications. For this purpose, we study 2D heterostructures consisting of graphene and monolayer TMDs by means of first-principles calculation and effective low-energy hamiltonian model. We determine the model parameters by fitting with the first-prinples bands. MoSe$_2$ and WSe$_2$ are chosen in order to align the Dirac cones of graphene with the intrinsic Fermi levels of the TMDs. It is found that the Dirac energy bands of graphene are modified, but the linear band dispersion near the cones is kept. It is shown that the effective low-energy model hosts Dirac-Rashba feimions in the WSe$_2$/graphene and MoSe$_2$/graphene/WSe$_2$, and there is quantum valley Hall effect in these graphene-based 2D heterostructures. Our further analyses indicate that there are strong interactions between the orbitals and spins especially near the K and K' points. These can be useful in further exploration for novel properties and more functionalities in 2D heterostructures.
format Preprint
id arxiv_https___arxiv_org_abs_2410_02542
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Dirac-Rashba fermions and quantum valley Hall insulators in graphene-based 2D heterostructures
Yu, Bo-Wen
Liu, Bang-Gui
Mesoscale and Nanoscale Physics
Materials Science
It is highly desirable to modify and improve the Dirac electron system of graphene for novel electronic properties and promising applications. For this purpose, we study 2D heterostructures consisting of graphene and monolayer TMDs by means of first-principles calculation and effective low-energy hamiltonian model. We determine the model parameters by fitting with the first-prinples bands. MoSe$_2$ and WSe$_2$ are chosen in order to align the Dirac cones of graphene with the intrinsic Fermi levels of the TMDs. It is found that the Dirac energy bands of graphene are modified, but the linear band dispersion near the cones is kept. It is shown that the effective low-energy model hosts Dirac-Rashba feimions in the WSe$_2$/graphene and MoSe$_2$/graphene/WSe$_2$, and there is quantum valley Hall effect in these graphene-based 2D heterostructures. Our further analyses indicate that there are strong interactions between the orbitals and spins especially near the K and K' points. These can be useful in further exploration for novel properties and more functionalities in 2D heterostructures.
title Dirac-Rashba fermions and quantum valley Hall insulators in graphene-based 2D heterostructures
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2410.02542