Transition metal dichalcogenide (TMDC) moiré superlattices, owing to the moiré flatbands and strong correlation, can host periodic electron crystals and fascinating correlated physics. The TMDC heterojunctions in the type-II alignment also enable long-lived interlayer excitons that are promising for correlated bosonic states, while the interaction is dictated by the asymmetry of the heterojunction. Here we demonstrate a new excitonic state, quadrupolar exciton, in a symmetric WSe2-WS2-WSe2 trilayer moiré superlattice. The quadrupolar excitons exhibit a quadratic dependence on the electric field, distinctively different from the linear Stark shift of the dipolar excitons in heterobilayers. This quadrupolar exciton stems from the hybridization of WSe2 valence moiré flatbands. The same mechanism also gives rise to an interlayer Mott insulator state, in which the two WSe2 layers share one hole laterally confined in one moiré unit cell. In contrast, the hole occupation probability in each layer can be continuously tuned via an out-of-plane electric field, reaching 100% in the top or bottom WSe2 under a large electric field, accompanying the transition from quadrupolar excitons to dipolar excitons. Our work demonstrates a trilayer moiré system as a new exciting playground for realizing novel correlated states and engineering quantum phase transitions.
Layer-Hybridized Wigner Crystals in MoSe2/WS2 Moiré Superlattice
Carnegie Mellon University（卡内基梅隆大学）；Arizona State University（亚利桑那州立大学）；National Institute for Materials Science（国立材料研究所）；The University of Texas at Dallas（德克萨斯大学达拉斯分校）；University of California at Riverside（加州大学河滨分校）
Robust valley-polarized excitonic Mott states and doublons enabled by stacking-controlled moiré geometry
National Taiwan University（国立台湾大学）；University of Washington（华盛顿大学）；National Institute for Materials Science（国家材料研究所）；Arizona State University（亚利桑那州立大学）
Highly nonlinear Moiré exciton and trion polaritons
Laboratory for Physical Sciences, University of Maryland（马里兰大学物理科学实验室）；University of Rochester（罗切斯特大学）；University of Notre Dame（圣母大学）；The Institute of Optics, University of Rochester（罗切斯特大学光学研究所）
$\mathbb Z_2$-Nontrivial Moiré Minibands and Interaction-Driven Quantum Anomalous Hall Insulators in Topological Insulator Based Moiré Heterostructures
Entangled Moire Chern Insulator in Rhombohedral Graphene
Peking University（北京大学）；National Institute of Material Sciences（国立材料研究所）；Collaborative Innovation Center of Quantum Matter（量子物质协同创新中心）；Hefei National Laboratory（合肥国家实验室）
Moiré Phonons and Emergent Exciton-Phonon Coupling in a Moiré Heterobilayer
University of California, Berkeley（加州大学伯克利分校）；Kavli Energy NanoScience Institute（卡弗里能源纳米科学研究所）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Indian Institute of Science（印度科学学院）；Newcastle University（纽卡斯尔大学）；National Institute for Materials Science（国立材料研究所）；University of Texas at Austin（德克萨斯大学奥斯汀分校）；Northeastern University（东北大学）
Experimental signature of layer skyrmions and implications for band topology in twisted WSe2 bilayers
University of Texas at Austin（德克萨斯大学奥斯汀分校）；The University of Hong Kong（香港大学）；National Yang Ming Chiao Tung University（阳明交通大学）；Pennsylvania State University（宾夕法尼亚州立大学）；National Institute for Materials Science（日本物质材料研究机构）
Real-Space Switching of Local Moments Driven by Quantum Geometry in Correlated Graphene Heterostructures
Universität Würzburg（维尔茨堡大学）；Würzburg-Dresden Cluster of Excellence ct.qmat（维尔茨堡-德累斯顿卓越集群 ct.qmat）；I. Institute of Theoretical Physics, Universität Hamburg（汉堡大学第一理论物理研究所）；The Hamburg Centre for Ultrafast Imaging（汉堡超快成像中心）；Department of Physics and Astronomy, Stony Brook University（石溪大学物理与天文学系）；Center for Computational Quantum Physics, Flatiron Institute（平顿研究所计算量子物理中心）
