The moiré superlattices of transition metal dichalcogenide heterobilayers have a pronounced effect on the optical properties of interlayer excitons (IXs) and have been intensively studied in recent years. However, the impact of moiré potentials on the temporal coherence of the IXs has not yet been investigated in detail. Here, we systematically investigate the coherence properties of both the ensemble of delocalized and the ensemble of localized IXs trapped in moiré potentials of the hexagonal boron nitride encapsulated WSe₂-MoSe₂ heterostructures. Our low-temperature first-order correlation measurements show that prolonged T₂ dephasing times with values up to 730 fs can be obtained from the ensemble of localized IXs under moderate pump powers. We observed up to almost a five-fold increase over the values we obtained from the delocalized IXs, while more than two-fold over the previously reported values of T₂ ~ 300 fs from the delocalized IXs. The prolonged values of T₂ dephasing times and narrow photoluminescence (PL) linewidths for the ensemble of moiré-trapped IXs compared to delocalized one indicate that dephasing mechanisms caused by exciton-low energy acoustic phonon and exciton-exciton scattering are significantly suppressed due to the presence of localization potentials. Our pump power-dependent T₂ results show that ultra-long dephasing times can be expected if the dephasing time measurements are performed with the narrow photoluminescence emission line of a single moiré-trapped IX at a low pump power regime. The prolonged values of IX dephasing times would be critical for the applications of quantum information science and the development of two-dimensional material-based nanolasers.

过渡金属二硫族化物异质双层的莫尔超晶格对层间激子（IX）的光学性质具有显着影响，近年来得到了深入研究。然而，莫尔势对 IX 时间相干性的影响尚未得到详细研究。在这里，我们系统地研究了六方氮化硼封装的WSe ₂ -MoSe ₂异质结构的莫尔势中的离域系综和局域IX系系的相干特性。我们的低温一阶相关测量表明，延长的T ₂在中等泵浦功率下，可以从局部 IX 的集合中获得高达 730 fs 的移相时间。我们观察到，与从离域 IX 获得的值相比，几乎增加了五倍，而与之前报道的从离域 IX 获得的T ₂  ~ 300 fs 值相比，增加了两倍多。与离域的相比，莫尔捕获的 IX 整体的 T 2 移相时间和窄光致发光 (PL) 线宽值更长，这表明由激子-低能声声子和激子-激子散射引起的移相机制被显着抑制_，因为存在本地化潜力。我们的泵依赖功率T ₂结果表明，如果在低泵浦功率状态下使用单个莫尔捕获 IX 的窄光致发光发射线进行移相时间测量，则可以预期超长的移相时间。延长 IX 相移时间对于量子信息科学的应用和基于二维材料的纳米激光器的开发至关重要。