首页|Visualizing the Local Twist Angle Variation within and between Domains of Twisted Bilayer Graphene

Visualizing the Local Twist Angle Variation within and between Domains of Twisted Bilayer Graphene

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Moiré superlattices in twisted two-dimensional materials have emerged as ideal platforms for engineering quantum phenomena,which are highly sensitive to twist angles,including both the global value and the spatial inhomogeneity.However,only a few methods provide spatial-resolved information for characterizing local twist angle distribution.Here we directly visualize the variations of local twist angles and angle-dependent evolutions of the quantum states in twisted bilayer graphene by scanning microwave impedance microscopy(sMIM).Spatially resolved sMIM measurements reveal a pronounced alteration in the local twist angle,approximately 0.3° over several micrometers in some cases.The variation occurs not only when crossing domain boundaries but also occasionally within individual domains.Additionally,the full-filling density of the flat band experiences a change of over 2 × 1011 cm-2 when crossing domain boundaries,aligning consistently with the twist angle inhomogeneity.Moreover,the correlated Chern insulators undergo variations in accordance with the twist angle,gradually weakening and eventually disappearing as the deviation from the magic angle increases.Our findings signify the crucial role of twist angles in shaping the distribution and existence of quantum states,establishing a foundational cornerstone for advancing the study of twisted two-dimensional materials.

户佳玮、朱诗雨、胡倩颖、王云昊、申承民、杨海涛、竺晓山、郇庆、许杨、高鸿钧

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Beijing National Center for Condensed Matter Physics,and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China

School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China

Hefei National Laboratory,Hefei 230088,China

国家自然科学基金国家自然科学基金国家重点研发计划国家重点研发计划国家重点研发计划中国科学院项目Innovation Program of Quantum Science and Technology

61888102123741992022YFA12041002019YFA03085012021YFA1401300XDB330301002021ZD0302700

2024

中国物理快报(英文版)
中国科学院物理研究所,中国物理学会

中国物理快报(英文版)

CSTPCDEI
影响因子:0.515
ISSN:0256-307X
年,卷(期):2024.41(3)
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