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arXiv 2302.09617cond-mat.mtrl-sci
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扭曲双层石墨烯中的扭曲角、应变、起伏与莫尔元胞

Twist Angle, Strain, Corrugation and Moire Unit cell in Twisted Bilayer Graphene

Veer Pal, Ajay

AI总结:

本研究全面分析了公度扭曲双层石墨烯的莫尔图案,开发了模拟碳原子平面位置的计算代码,发现表观莫尔周期与实际周期存在差异,证明了应变与破缺旋转对称性的内禀性,并验证了表观应变计算值与实验结果的一致性。

摘要:

本工作对公度扭曲双层石墨烯(TBG)中的莫尔图案进行了全面研究,以确定莫尔周期与相应扭曲角之间的联系。基于对莫尔图案的理解,开发了计算代码来模拟任意公度扭曲角下,位于大尺寸公度扭曲双层石墨烯(CTBG)样品中碳原子的平面位置。借助CTBG的模拟莫尔图案,证明了对于许多公度扭曲角,表观莫尔周期可能与实际莫尔周期大不相同,并且相同的莫尔图案可能具有多个略有不同的表观莫尔周期值。这些多个略有不同的表观莫尔周期值表明,CTBG莫尔图案中的应变和破缺旋转对称性是内禀的。根据表观莫尔周期的不同值,计算了许多公度扭曲角下CTBG莫尔图案中的表观应变;计算得出的表观应变值与实验报告值吻合良好。结合从与扭曲双层石墨烯系统和传统双层石墨烯系统相关的可用实验数据中获得的一些见解,对CTBG中的起伏进行了建模,并将其与模拟的碳原子位置相结合。

英文摘要:

This work put forward a comprehensive study of moire pattern in commensurate twisted bilayer graphene (TBG) to determine the connection of moire period with corresponding twist angle. Using the understanding of moire pattern, computational codes are developed to simulate the planar positions of carbon atoms lying in a large specimen of commensurate twisted bilayer graphene (CTBG) with any commensurate twist angle. With the help of simulated moire patterns of CTBG it is demonstrated that for many commensurate twist angles the apparent moire period may be quite different from the actual moire period, and the same moire pattern may have multiple slightly different values of the apparent moire period. These multiple slightly different values of the apparent moire period show that strain and broken rotational symmetry in moire pattern of CTBG are intrinsic. From various values of apparent moire period, the apparent strain in moire pattern of CTBG is calculated for many commensurate twist angles; the calculated values of apparent strain are in good agreement with experimentally reported values. Taking some insight from available experimental data related to twisted bilayer graphene systems and conventional bilayer graphene systems, corrugation in CTBG is modelled and incorporated with the simulated positions of carbon atoms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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