School of Physics and Electronics, Hunan Key Laboratory for Super-microstructure and Ultrafast Process, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, People's Republic of China.
State Key Laboratory of High-Performance Complex Manufacturing, Central South University, 932 South Lushan Road, Changsha, Hunan, 410083, People's Republic of China.
Small. 2023 Jun;19(26):e2207988. doi: 10.1002/smll.202207988. Epub 2023 Mar 20.
The exploration of moiré superlatticesholds promising potential to uncover novel quantum phenomena emerging from the interplay of atomic structure and electronic correlation . However, the impact of the moiré potential modulation on the number of twisted layers has yet to be experimentally explored. Here, this work synthesizes a twisted WSe homotrilayer using a dry-transfer method and investigates the enhancement of the moiré potential with increasing number of twisted layers. The results of the study reveal the presence of multiple exciton resonances with positive or negative circularly polarized emission in the WSe homostructure with small twist angles, which are attributed to the excitonic ground and excited states confined to the moiré potential. The distinct g-factor observed in the magneto-optical spectroscopy is also shown to be a result of the confinement of the exciton in the moiré potential. The moiré potential depths of the twisted bilayer and trilayer homostructures are found to be 111 and 212 meV, respectively, an increase of 91% from the bilayer structure. These findings demonstrate that the depth of the moiré potential can be manipulated by adjusting the number of stacked layers, providing a promising avenue for exploration into highly correlated quantum phenomena.
莫尔超晶格的探索有望揭示出由原子结构和电子关联相互作用产生的新颖量子现象。然而，莫尔势调制对扭曲层数的影响尚未在实验中得到探索。在这里，这项工作使用干法转移法合成了扭曲的 WSe 三层同型异质结构，并研究了随着扭曲层数的增加，莫尔势的增强。研究结果表明，在小扭曲角的 WSe 同型结构中存在多个具有正或负圆偏振发射的激子共振，这归因于激子基态和激发态被限制在莫尔势中。在磁光光谱中观察到的明显的 g 因子也被证明是激子在莫尔势中的限制的结果。发现扭曲双层和三层同型异质结构的莫尔势深度分别为 111 和 212 meV，比双层结构增加了 91%。这些发现表明，通过调整堆叠层数可以操纵莫尔势的深度，为探索高度相关的量子现象提供了一个有前途的途径。
