论文标题
双重周期性Moiré超级晶格的实验实现$ _2 $/WSE $ _2 $ HETEROBILAYER
Experimental realisation of Dual Periodicity Moiré Superlattice in a MoSe$_2$/WSe$_2$ Heterobilayer
论文作者
论文摘要
范德华异质结构中的Moiré结构导致新兴现象，包括扭曲的双层石墨烯中的超导性和在过渡金属二甲藻元化元素异叶剂中的光学上可访问的强相关电子状态。在具有两层以上的分层结构中形成的双重周期性莫伊尔结构（DPM）已显示出导致铁磁性和TBG中的多个次要狄拉克点。尽管原则上可以在双层中获得DPM，但尚未有明确的实验证据。在本文中，我们在扭曲的摩西$ _2 $/WSE $ _2 $ biLayer中介绍了DPM的签名，由共鸣拉曼光谱显示。我们观察到带有波德向量的莫伊尔波向量两次的区域折叠的声音和光学声子模式，这是双周期性莫伊尔异质结构的证据。这些结果同时为新的新兴现象开辟了机会，并为在广泛的范德华异质结构中表征DPM的光学方法。
Moiré structures in van der Waals heterostructures lead to emergent phenomena including superconductivity in twisted bilayer graphene and optically accessible strongly-correlated electron states in transition metal dichalcogenide heterobilayers. Dual periodicity moiré structures (DPMS) formed in layered structures with more than two layers have been shown to lead to ferromagnetism and multiple secondary Dirac points in TBG. Whilst in principle it is possible to obtain DPMS in bilayers there has not been clear experimental evidence of this yet. In this paper we present signatures of DPMS in a twisted MoSe$_2$/WSe$_2$ bilayer revealed by resonance Raman spectroscopy. We observed zone-folded acoustic and optical phonon modes with a wavevector twice of the moiré wavevector, evidence of a dual periodicity moiré heterostructure. These results simultaneously open up opportunities for new emergent phenomena and an optical method for characterising DPMS in a wide range of van der Waals heterostructures.
