Wang Renqi, Chang Kai, Duan Wenhui, Xu Yong, Tang Peizhe
State Key Laboratory of Low-Dimensional Quantum Physics, and Department of Physics, Tsinghua University, Beijing 100084, China.
Zhejiang University, Center for Quantum Matter, Hangzhou 310058, China.
Phys Rev Lett. 2025 Jan 17;134(2):026904. doi: 10.1103/PhysRevLett.134.026904.
Twistronics, which utilizes the moiré potential to induce exotic excitations in twisted material systems, has garnered significant attention in recent years. In this Letter, using the Bethe-Salpeter calculations based on a continuum model of electronic structures, we explore the optical characteristics of intralayer moiré excitons in twisted bilayer transition metal dichalcogenide heterostructures. We find the Coulomb exchange interactions strongly influence these excitons and the degree of valley polarization and that the splitting between spin-singlet and spin-triplet moiré excitons can be effectively controlled by varying the twist angle. Specifically, intralayer bright spin-singlet moiré excitons confined in a twisted WSe_{2}/WS_{2} heterostructure can achieve valley polarization levels as high as 90% at small twist angles, which holds promise for future applications in valleytronics. These findings underscore the twist angle as a novel parameter for manipulating the optical properties of moiré excitons, thereby establishing moiré semiconductors as a promising platform for investigating many-body physics in solid-state systems.
扭曲电子学利用莫尔势在扭曲材料系统中诱导奇异激发，近年来备受关注。在本信函中，我们基于电子结构的连续模型，利用贝叶斯 - 萨尔皮特计算方法，探索了扭曲双层过渡金属二硫属化物异质结构中层内莫尔激子的光学特性。我们发现库仑交换相互作用强烈影响这些激子和谷极化程度，并且通过改变扭曲角可以有效控制自旋单重态和自旋三重态莫尔激子之间的分裂。具体而言，在扭曲的WSe₂/WS₂异质结构中受限的层内明亮自旋单重态莫尔激子在小扭曲角下可实现高达90%的谷极化水平，这为未来在谷电子学中的应用带来了希望。这些发现强调了扭曲角作为操纵莫尔激子光学性质的新参数，从而确立了莫尔半导体作为研究固态系统中多体物理的有前景平台。
