标题： 单层1T相过渡金属二硫属化物的轨道纹理及关联绝缘态的演化 显示英文标题

标题： Orbital textures and evolution of correlated insulating state in monolayer 1T phase transition metal dichalcogenides

摘要： 强电子-电子相互作用可以诱导莫特绝缘态，这种状态被认为在量子涨落占主导时会表现出诸如量子自旋液体等不寻常的相关现象，并通过掺杂实现非常规超导性。过渡金属化合物作为关联材料，为工程化莫特绝缘态提供了多功能平台。以往的研究主要集中在通过门控或掺杂来控制电子的排斥相互作用和能带宽度。在这里，我们对单层1T相的NbSe2、TaSe2和TaS2进行了角分辨光电子能谱（ARPES）研究，并直接观察到了它们的能带结构，具有特征性的低 Hubbard 带。通过系统地研究该家族材料的轨道纹理和能隙的温度依赖性，我们发现硫属元素p态与低Hubbard带的杂化通过调节能带宽度稳定了莫特相，如在更强的杂化强度下，转变温度（TC）显著增加所示。我们的发现揭示了一种实现稳健莫特绝缘相的机制，并确立了单层1T相过渡金属二硫化物家族作为探索关联电子问题的有前景的平台。 显示英文摘要

摘要： Strong electron-electron interaction can induce Mott insulating state, which is believed to host unusual correlated phenomena such as quantum spin liquid when quantum fluctuation dominates and unconventional superconductivity through doping. Transition metal compounds as correlated materials provide a versatile platform to engineer the Mott insulating state. Previous studies mostly focused on the controlling of the repulsive interaction and bandwidth of the electrons by gating or doping. Here, we performed angle-resolved photoemission spectroscopy (ARPES) on monolayer 1T phase NbSe2, TaSe2, and TaS2 and directly observed their band structures with characteristic lower Hubbard bands. By systematically investigating the orbital textures and temperature dependence of the energy gap of the materials in this family, we discovered that hybridization of the chalcogen p states with lower Hubbard band stabilizes the Mott phase via tuning of the bandwidth, as shown by a significant increase of the transition temperature (TC) at a stronger hybridization strength. Our findings reveal a mechanism for realizing a robust Mott insulating phase and establish monolayer 1T phase transition metal dichalcogenide family as a promising platform for exploring correlated electron problems.