发表机构
Peking University; Academy for Advanced Interdisciplinary Studies, Peking University; The University of Hong Kong; University of Chinese Academy of Sciences; HK Institute of Quantum Science & Technology, The University of Hong Kong; Zhengzhou University; National Institute for Materials Science; Liaoning Academy of Materials; ShanghaiTech University; South China Normal University; Songshan Lake Materials Laboratory（北京大学; 北京大学前沿交叉学科研究院; 香港大学; 中国科学院大学; 香港大学量子科学与技术研究所; 郑州大学; 物质材料研究机构; 辽宁省材料科学研究院; 上海科技大学; 华南师范大学; 松山湖材料实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合栅极可调光谱与第一性原理计算，揭示WSe₂/Nb₃Cl₈异质结构中激子探测莫特间隙、形成极化子及磁场下谷选择性耦合，拓展了激子传感至平带莫特材料。
AI 中文摘要
激子为邻近二维材料中的电子关联提供了灵敏的光学探针，然而它们与本征平带莫特系统的耦合在很大程度上仍未得到探索。在此，我们将栅极可调光学光谱与第一性原理计算相结合，研究直接接触范德华莫特绝缘体Nb$_3$Cl$_8$的单层WSe$_2$。WSe$_2$激子共振的栅极演化揭示了Nb$_3$Cl$_8$中关联重构的莫特间隙的特征，而这种特征在单粒子能带图像中是不存在的。在电子掺杂区域，WSe$_2$的2s里德伯激子经历多阶段演化，并发展成层间吸引和排斥极化子分支，表明里德伯激子可以被相邻莫特层中强关联的平带电子所修饰。在垂直磁场下，自旋极化的Nb$_3$Cl$_8$态进一步诱导谷选择性激子耦合，产生WSe$_2$激子发射的强烈增强的圆偏振。这些结果将基于激子的传感和激子极化子物理扩展到本征平带莫特材料，为探测和工程化关联驱动的界面准粒子提供了一条光学途径。
英文摘要
Excitons provide a sensitive optical probe of electronic correlations in nearby two-dimensional materials, yet their coupling to intrinsic flat-band Mott systems remains largely unexplored. Here we combine gate-tunable optical spectroscopy with first-principles calculations to study monolayer WSe$_2$ in direct contact with the van der Waals Mott insulator Nb$_3$Cl$_8$. The gate evolution of WSe$_2$ excitonic resonances reveals signatures of a correlation-reconstructed Mott gap in Nb$_3$Cl$_8$ that is absent from the single-particle band picture. In the electron-doped regime, the WSe$_2$ 2s Rydberg exciton undergoes a multistage evolution and develops into interlayer attractive and repulsive polaron branches, showing that a Rydberg exciton can be dressed by strongly correlated flat-band electrons in an adjacent Mott layer. Under an out-of-plane magnetic field, spin-polarized Nb$_3$Cl$_8$ states further induce valley-selective exciton coupling, producing a strongly enhanced circular polarization of the WSe$_2$ exciton emission. These results extend exciton-based sensing and exciton-polaron physics to intrinsic flat-band Mott materials, providing an optical route to probe and engineer correlation-driven interfacial quasiparticles.
Comments9 pages, 4 figures
