Interlayer excitons in layered materials constitute a novel platform to study many-body phenomena arising from long-range interactions between quantum particles. Long-lived excitons are required to achieve high particle densities, to mediate thermalisation, and to allow for spatially and temporally correlated phases. Additionally, the ability to confine them in periodic arrays is key to building a solid-state analogue to atoms in optical lattices. Here, we demonstrate interlayer excitons with lifetime approaching 0.2 ms in a layered-material heterostructure made from WS₂ and WSe₂ monolayers. We show that interlayer excitons can be localised in an array using a nano-patterned substrate. These confined excitons exhibit microsecond-lifetime, enhanced emission rate, and optical selection rules inherited from the host material. The combination of a permanent dipole, deterministic spatial confinement and long lifetime places interlayer excitons in a regime that satisfies one of the requirements for simulating quantum Ising models in optically resolvable lattices.

层状材料中的层间激子构成了研究由量子粒子之间的长程相互作用引起的多体现象的新平台。需要长寿命的激子来实现高粒子密度，调节热化，并允许空间和时间相关的相位。此外，将它们限制在周期性阵列中的能力是构建光学晶格中原子的固态模拟的关键。在这里，我们展示了在由 WS ₂和 WSe ₂制成的层状材料异质结构中寿命接近 0.2 ms 的层间激子单层。我们表明可以使用纳米图案基板将层间激子定位在阵列中。这些受限激子具有微秒寿命、增强的发射率和从主体材料继承的光学选择规则。永久偶极子、确定性空间限制和长寿命的组合将层间激子置于满足在光学可分辨晶格中模拟量子 Ising 模型的要求之一的状态。