论文标题
调音带差距中的扭曲双层MOS $ _2 $
Tuning band gaps in twisted bilayer MoS$_2$
论文作者
论文摘要
在扭曲的双层结构的新兴世界中，可能的配置是无限的，可以实现丰富的电子特性景观。在本文中，我们专注于扭曲的双层过渡金属二核苷（TMDC），并通过精确的紧密结合模型来研究其特性。我们建立不同角度的结构，发现当扭曲角度足够小（约7.3 $^{\ circ} $）时，所谓的悬条出现。有趣的是，当放松样本中的扭曲角度从21.8 $^{\ circ} $到0.8 $^{\ circ} $时，频段隙可以调整为2.2 \％（51 meV）。此外，当查看状态的局部密度时，我们发现由于不同位点的层之间的耦合发生了变化，因此频带间隙沿Moirè模式在本地变化。最后，我们还发现，当应用足够强的电场时，该系统可能会遭受从半导体向金属的过渡。我们的研究可以作为基于TMDCS的光电设备实践工程的指南。
In the emerging world of twisted bilayer structures, the possible configurations are limitless, which enables for a rich landscape of electronic properties. In this paper, we focus on twisted bilayer transition metal dichalcogenides (TMDCs) and study its properties by means of an accurate tight-binding model. We build structures with different angles and find that the so-called flatbands emerge when the twist angle is sufficiently small (around 7.3$^{\circ}$). Interestingly, the band gap can be tuned up to a 2.2\% (51 meV) when the twist angle in the relaxed sample varies from 21.8$^{\circ}$ to 0.8$^{\circ}$. Furthermore, when looking at local density of states we find that the band gap varies locally along the moirè pattern due to the change in the coupling between layers at different sites. Finally, we also find that the system can suffer a transition from a semiconductor to a metal when a sufficiently strong electric field is applied. Our study can serve as a guide for the practical engineering of the TMDCs based optoelectronic devices.
