Moiré superlattices can be used to engineer strongly correlated electronic states in two-dimensional van der Waals heterostructures, as recently demonstrated in the correlated insulating and superconducting states observed in magic-angle twisted-bilayer graphene and ABC trilayer graphene/boron nitride moiré superlattices^1,2,3,4. Transition metal dichalcogenide moiré heterostructures provide another model system for the study of correlated quantum phenomena⁵ because of their strong light–matter interactions and large spin–orbit coupling. However, experimental observation of correlated insulating states in this system is challenging with traditional transport techniques. Here we report the optical detection of strongly correlated phases in semiconducting WSe₂/WS₂ moiré superlattices. We use a sensitive optical detection technique and reveal a Mott insulator state at one hole per superlattice site and surprising insulating phases at 1/3 and 2/3 filling of the superlattice, which we assign to generalized Wigner crystallization on the underlying lattice^{6,7,8,9,10,11}. Furthermore, the spin–valley optical selection rules^12,13,14 of transition metal dichalcogenide heterostructures allow us to optically create and investigate low-energy excited spin states in the Mott insulator. We measure a very long spin relaxation lifetime of many microseconds in the Mott insulating state, orders of magnitude longer than that of charge excitations. Our studies highlight the value of using moiré superlattices beyond graphene to explore correlated physics.

莫尔超晶格可用于设计二维范德华异质结构中的强相关电子态，如最近在魔角扭曲双层石墨烯和 ABC 三层石墨烯/氮化硼莫尔超晶格中观察到的相关绝缘和超导状态中所证明的^{1， 2,3,4}。过渡金属二硫属化物莫尔异质结构为研究相关量子现象⁵提供了另一个模型系统，因为它们具有很强的光-物质相互作用和大的自旋-轨道耦合。然而，该系统中相关绝缘状态的实验观察对于传统传输技术具有挑战性。_{在这里，我们报告了半导体 WSe 2}中强相关相的光学检测/WS ₂莫尔超晶格。我们使用灵敏的光学检测技术，并在每个超晶格位置一个孔处显示莫特绝缘体状态，并在超晶格的 1/3 和 2/3 填充处显示出令人惊讶的绝缘相，我们将其分配给底层晶格上的广义 Wigner 结晶^{6,7 ,8,9,10,11}。此外，自旋谷光学选择规则^12,13,14过渡金属二硫化物异质结构的研究使我们能够光学地创建和研究莫特绝缘体中的低能激发自旋态。我们在莫特绝缘状态下测量了许多微秒的非常长的自旋弛豫寿命，比电荷激发的寿命长几个数量级。我们的研究强调了使用石墨烯以外的莫尔超晶格来探索相关物理的价值。