30°转角双层WSe₂中十二重复制带的观测
Observation of dodecagonal replica bands in 30$^{\circ}$-twisted bilayer WSe$_2$
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中文总结 AI 辅助
本研究利用微米级空间分辨率的角分辨光电子能谱，观测到30°转角双层WSe₂中的十二重复制带，揭示其由层间Umklapp散射产生，且K谷附近存在范霍夫奇点，为大转角双层结构的电子调控提供依据。
中文摘要 AI 辅助
二维过渡金属二硫化物的转角双层结构是实现具有新奇性质的可调准晶有序的有潜力体系。迄今为止，具有多轨道十二重复制带的二维准晶的基础电子结构与散射过程尚未被确定。本研究采用具有微米级空间分辨率的角分辨光电子能谱（ARPES），直接观测了30°转角双层WSe₂中的复制带。观测到的复制带的对称性与强度分布可由从底层WSe₂到顶层WSe₂的层间Umklapp散射解释。我们的谱函数测量结果与K谷附近存在范霍夫奇点的情况一致，这凸显了在具有大层间转角的双层结构中诱导电子重构的可能性。
英文摘要
Twisted bilayers of two-dimensional (2D) transition metal dichalcogenides are promising systems for achieving tunable quasicrystalline orders with emergent properties. The underpinning electronic structure and scattering processes in 2D quasicrystals with multiorbital dodecagonal replica bands have so far not been determined. Here, we utilize angle-resolved photoemission spectroscopy (ARPES) with micrometer spatial resolution to directly observe replica bands in 30$^{\circ}$-twisted bilayer WSe$_2$. The symmetry and intensity distribution of the observed replicas are explained by interlayer Umklapp scattering from bottom to top WSe$_2$ layers. Our spectral function measurements are consistent with the presence of a van Hove singularity adjacent to the $\mathrm{K}$-valleys, which underlines the possibility of inducing electronic reconstructions in bilayers with a large interlayer twist angle.
