Gatti G, Issing J, Rademaker L, Margot F, de Jong T A, van der Molen S J, Teyssier J, Kim T K, Watson M D, Cacho C, Dudin P, Avila J, Edwards K Cordero, Paruch P, Ubrig N, Gutiérrez-Lezama I, Morpurgo A F, Tamai A, Baumberger F
Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland.
Department of Theoretical Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland.
Phys Rev Lett. 2023 Jul 28;131(4):046401. doi: 10.1103/PhysRevLett.131.046401.
The recent observation of correlated phases in transition metal dichalcogenide moiré systems at integer and fractional filling promises new insight into metal-insulator transitions and the unusual states of matter that can emerge near such transitions. Here, we combine real- and momentum-space mapping techniques to study moiré superlattice effects in 57.4° twisted WSe_{2} (tWSe_{2}). Our data reveal a split-off flat band that derives from the monolayer Γ states. Using advanced data analysis, we directly quantify the moiré potential from our data. We further demonstrate that the global valence band maximum in tWSe_{2} is close in energy to this flat band but derives from the monolayer K states which show weaker superlattice effects. These results constrain theoretical models and open the perspective that Γ-valley flat bands might be involved in the correlated physics of twisted WSe_{2}.
最近在整数和分数填充的过渡金属二硫属化物莫尔系统中观察到的相关相，有望为金属-绝缘体转变以及在此类转变附近可能出现的异常物质状态提供新的见解。在这里，我们结合实空间和动量空间映射技术，研究57.4°扭曲的WSe₂（tWSe₂）中的莫尔超晶格效应。我们的数据揭示了一个源自单层Γ态的分裂平带。通过先进的数据分析，我们直接从数据中量化了莫尔势。我们进一步证明，tWSe₂中的全局价带最大值在能量上与这个平带接近，但源自单层K态，其显示出较弱的超晶格效应。这些结果限制了理论模型，并开启了Γ谷平带可能参与扭曲WSe₂相关物理的前景。
