课题组博士生吴彪同学在国际纳米权威期刊Nano Research上发表论文

2022-08-31 16:06:41 284

课题组博士生吴彪同学在国际纳米权威期刊Nano Research上发表论文

       近日，课题组博士生吴彪同学在刘老师的指导下，以第一作者在国际纳米权威期刊《纳米研究》(Nano Research，影响因子10.269)上发表题为“Effect of layered-coupling in twisted WSe2 moiré superlattices”(扭角WSe2莫尔超晶格中的层数的耦合效应)的实验论文。

图片关键词 

图：扭角WSe2莫尔超晶格中的层数的耦合效应

      最近，在两个不同单层的扭曲垂直堆叠中发现了多种与莫尔相关的特性，引起了相当大的关注。在过渡金属二硫属化物 (TMD) 异质结构中引入小扭转角导致莫尔势的出现，这为研究电子的强相互作用提供了一个新型的平台。尽管目前对扭曲双层超晶格中的莫尔激子进行了广泛的研究，但在具有层耦合效应的同构超晶格中捕获和研究莫尔激子仍然是一个挑战问题。本文中，我们展示了对具有各种层耦合相互作用的扭角1L-WSe2/1L-WSe2 和 1L-WSe2/2L-WSe2同质结中的莫尔激子的观察。结果表明，随着底层层数数量的减少，莫尔势增加了~260％，表明不同层的耦合效应对莫尔势能调制的影响。进一步证明了温度和激光功率依赖性以及谷极化对莫尔激子的影响，并解释了观察到的关键光谱特征。我们的发现为探索量子现象和量子信息的相关应用铺平了道路。

论文链接：https://link.springer.com/article/10.1007/s12274-022-5007-x

Comments:

  • The layered coupling in twisted WSe2 moiré superlattices has a significant impact on the electronic properties of the system. This coupling is the result of the overlapping of the WSe2 layers in the superlattice and the resulting interactions between them.

  • One of the most notable effects of the layered coupling is the formation of new electronic bands in the superlattice. These bands arise from the hybridization of the WSe2 layers and have different energies and orbital characteristics compared to the individual layers. As a result, the superlattice exhibits new electronic states and a modified density of states (DOS).

  • Another important effect of the layered coupling is the modulation of the energy gaps between the bands. In WSe2 monolayers, the bandgap is indirect and varies depending on the layer orientation. However, in the twisted WSe2 moiré superlattice, the bandgap is direct and becomes more pronounced due to the enhanced interaction between the layers. This leads to improved electronic and optical properties, including a larger bandgap and a higher degree of polarization.

  • Finally, the layered coupling in twisted WSe2 moiré superlattices also leads to a modification of the electronic band structure near the Fermi level. This can result in new states at the Fermi level, which can impact the electrical conductivity of the superlattice.

  • In conclusion, the layered coupling in twisted WSe2 moiré superlattices plays a crucial role in determining the electronic properties of the system. The coupling leads to the formation of new electronic states, the modulation of the energy gaps, and a modification of the band structure near the Fermi level.