Probing the special angle in twisted bilayer MoS_(2)via angle-dependent scanning tunneling microscopy studies  

作　　者：Xueying Liu Shiying Liu Yulong Xiao Chang Xu Jiaxin Wu Kaihui Li Si-Yu Li Anlian Pan 

机构地区：[1]Key Laboratory for Micro-Nano Physics and Technology of Hunan Province,Hunan Institute of Optoelectronic Integration and College of Materials Science and Engineering,Hunan University,Changsha,410082,China [2]School of Physics and Electronics,Hunan Normal University,Changsha,410081,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2025年第2期153-160,共8页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Key R&D Program of China(Grant Nos.2022YFA1204700,and 2022YFA1204300);the National Natural Science Foundation of China(Grant Nos.12104144,52221001,and62090035);the Key Research and Development Plan of Hunan Province(Grant No.2023GK2012)。

摘　　要：Twisted transition metal dichalcogenides(TMDs)homo-bilayers host unique quantum properties,which can be tuned by interlayer twist angleθ.However,the systematic evolution of their typical electronic properties with respect to the twist angleθ,which is crucial for identifying the“special angle”analogous to the“magic angle”of twisted bilayer graphene in correlation physics studies,remains incompletely understood.Here,via scanning tunneling microscopy(STM)and spectroscopy(STS),we investigate the variation of the moirépotential,flat band,and layer polarization characteristics across a wide range of twist angleθin twisted bilayer MoS_(2)(TB-MoS_(2)).The moirépotential of the valence band exhibits a non-monotonic variation withθ,peaking at a maximum value up to 204 me Vatθ~1.7°.Concurrently,at the sameθ,the bandwidth of the flat band at theΓ_(V)point of the valence band attains its minimum,precisely signifying the“special angle”θ_(c)~1.7°in TB-MoS_(2).Interestingly,layer polarization in the moirésuperlattice is spatially visualized through the distribution of local density of states(LDOS)at the energies of bothΓ_(V)and K_(V)points of the valence band,where the polarization degree at theΓ_(V)point demonstrates a close dependency onθ.Our findings deepen understanding of twist-angle effect in TMDs,advancing both fundamental physics and practical application.

关 键 词：twisted bilayer MoS_(2) flat band moirépotential twist-angle dependence scanning tunneling microscopy 

分 类 号：O469[理学—凝聚态物理] TQ136.12[理学—电子物理学]