论文标题
WSE $ _2 $ -MOSE $ _2 $ HETEROBILAYERS中的低频拉曼散射：原子重建的证据
Low-frequency Raman scattering in WSe$_2$-MoSe$_2$ heterobilayers: Evidence for atomic reconstruction
论文作者
论文摘要
我们调查了WSE $ _2 $ -MOSE $ _2 $异质分子，具有不同的扭转角$θ\ pmδ$在两层之间，低频拉曼散射。在具有$θ= 0^\ circ $的足够对齐的样品中，或$θ= 60^\ circ $和$δ\ lyssim 3^\ circ $，我们观察到一个间层间剪切模式（ISM），这显然是相称的双层结构，即，层次不足，即在一个不足的居民或构造的状态下，或者构造了一个形式，即构造或构造。我们发现略有不同的ISM能量分别为H-type和R-Type重建，约为18〜cm $^{ - 1} $和17〜cm $^{ - 1} $，独立于$θ\ pmΔ$的确切值。我们的发现得到了以下事实，即在具有扭曲角度的样品中观察到ISM的事实，从$ 0^\ circ $或$ 60^\ circ $偏离$δ> 3^\ circ $。这是可以预期的，因为在这样的不相称的结构中，Moir $ \ actecute {\ text {e}} $ - 晶格形成的可能性，ISM没有恢复力。此外，我们即使在足够比对的异叶剂中观察到ISM，这些杂词被封装在硝化氢硼中。这与高质量异质结构设备的表征特别相关。
We investigate WSe$_2$-MoSe$_2$ heterobilayers with different twist angles $θ\pm δ$ between the two layers, by low-frequency Raman scattering. In sufficiently aligned samples with $θ=0^\circ$, or $θ=60^\circ$, and $δ\lesssim 3^\circ$, we observe an interlayer shear mode (ISM), which is a clear sign of a commensurate bilayer structure, i.e., the layers must undergo an atomic reconstruction to form R-type or H-type stacking orders. We find slightly different ISM energies of about 18~cm$^{-1}$ and 17~cm$^{-1}$ for H-type and R-type reconstructions, respectively, independent of the exact value of $θ\pm δ$. Our findings are corroborated by the fact that the ISM is not observed in samples with twist angles, which deviate by $δ> 3^\circ$ from $0^\circ$ or $60^\circ$. This is expected, since in such incommensurate structures, with the possibility of Moir$\acute{\text{e}}$-lattice formation, there is no restoring force for an ISM. Furthermore, we observe the ISM even in sufficiently aligned heterobilayers, which are encapsulated in hexagonal Boron nitride. This is particularly relevant for the characterization of high-quality heterostructure devices.
