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

IF 4.6 2区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

iScience Pub Date : 2025-06-04 DOI:10.1016/j.isci.2025.112818

Bo-Wen Yu , Bang-Gui Liu

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引用次数: 0

Abstract

For promising Dirac electronic properties and functionalities, we study five 2D heterostructures consisting of graphene and monolayer transition metal dichalcogenides by means of first-principles investigation and an effective low-energy model. It is revealed from first-principles bands that the Dirac energy bands are gapped (0.1

\sim

0.5 meV) and their relativistic dispersions are robust up to the energy window of 0.4 eV at least. The model parameters are determined by fitting the first-principles calculated bands in each of the heterostructures. It is shown that Dirac-Rashba fermions are hosted in the

{WSe}_{2}

/graphene and

{MoSe}_{2}

/graphene/WSe₂, and quantum valley Hall insulators can be achieved in all these heterostructures. Further analysis elucidates features of Berry curvature distribution and interactions of the orbitals and spins. These can be useful in future exploration for more effects and functionalities in 2D heterostructures.

Abstract Image

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石墨烯二维异质结构中的Dirac-Rashba费米子和量子谷霍尔绝缘子

为了研究有前景的狄拉克电子性质和功能，我们利用第一性原理研究和有效的低能模型研究了由石墨烯和单层过渡金属二硫族化合物组成的五种二维异质结构。从第一性原理波段可以看出，Dirac能带是有间隙的（0.1 ~ 0.5 meV），它们的相对论色散至少在0.4 eV的能量窗口内是稳健的。模型参数通过拟合每个异质结构的第一性原理计算带来确定。结果表明，在WSe2/石墨烯和MoSe2/石墨烯/WSe2中存在Dirac-Rashba费米子，并且在所有这些异质结构中都可以实现量子谷霍尔绝缘子。进一步的分析阐明了贝里曲率分布的特征以及轨道和自旋的相互作用。这些可以为未来探索二维异质结构的更多效应和功能提供帮助。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

iScience Multidisciplinary-Multidisciplinary

CiteScore

7.20

自引率

1.70%

发文量

1972

审稿时长

6 weeks

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