非扭转双层石墨烯中异质应变诱导的平带

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中文摘要：双层石墨烯中扭转诱导的晶格失配会导致摩尔纹图案并产生具有强关联效应的平带，但这需要复杂的过程来精确控制扭转角度。这里，通过分别沿两个不同的扶手椅方向单轴拉伸上下层石墨烯，我们提出了一种不同的方法来生成双层石墨烯中的六边形摩尔纹。两个石墨烯层之间的变形导致了等效于扭角石墨烯中的错位角，异质应变诱导的摩尔纹在费米能级附近产生平带，表现出和扭角双层石墨烯等效的电子性质。我们证明2。1％异质应变下的电子平带等价于1。05°第一魔角下的能带。然而，由于单轴应变，狄拉克点相对于K点轻微偏移，将平带分成两个相隔18 meV的分别位于费米能级上方和下方的范霍夫奇点峰。我们的研究结果提出了一种控制自然双层石墨烯电子强关联性的可能方法。

外文标题：Heterostrain-induced flat bands in untwisted bilayer graphene

外文摘要：Twist-induced lattice misalignment of bilayer graphene leads to moire patterns that generate electronic flat bands with strongly correlated electronic states,but it still requires a sophisticated process to precisely control the twist angle.Here,we propose a different way to generate hexagonal moirés in bilayer graphene by uniaxially stretching the two layers along two distinct armchair directions,respectively.The heterostrain-induced moiré gives rise to flat bands near the Fermi level due to the deformation-induced equivalent misaligned angle between two graphene layers,featuring an electronic equivalence of twisted bilayer graphene.We demonstrate the flat bands at a heterostrain of 2.1％,equivalent to the first magic angle of 1.05°.Yet,a slight shift of Dirac point from K point due to the uniaxial strain splits the flat bands into two van Hove singularity peaks that are separated by 18 meV and located above and below the Fermi level,respectively.Our results suggest a potential way to control the electronic strong correlation in bilayer graphene of natural stacking.

外文关键词：

StrainBilayer grapheneFlat bandContinuum model

作者：

杭阳、张助华

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作者单位：

State Key Laboratory of Mechanics and Control for Aerospace Structures,Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education,and Institute for Frontier Science,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China

关键词：

Strain Bilayer graphene Flat band Continuum model

基金：

国家重点研发计划National NSF of ChinaNational NSF of ChinaNational NSF of ChinaNational NSF of China江苏高校优势学科建设工程项目江苏省自然科学基金Jiangsu Funding Program for Excellent Postdoctoral Talent

项目编号：

2019YFA0705400122611603671222520522073048BK202208722022ZB232

出版年：

2024

DOI：

10.1007/s10409-023-23176-x

力学学报(英文版)

CSTPCD

影响因子：0.363

ISSN：0567-7718

年,卷(期)：2024.40(1)

参考文献量52