The interplay of electronic correlations, spin–orbit coupling and topology holds promise for the realization of exotic states of quantum matter. Models of strongly interacting electrons on honeycomb lattices have revealed rich phase diagrams featuring unconventional quantum states including chiral superconductivity and correlated quantum spin Hall insulators intertwining with complex magnetic order. Material realizations of these electronic states are, however, scarce or inexistent. In this work, we propose and show that stacking 1T-TaSe₂ into bilayers can deconfine electrons from a deep Mott insulating state in the monolayer to a system of correlated Dirac fermions subject to sizable spin–orbit coupling in the bilayer. 1T-TaSe₂ develops a Star-of-David charge density wave pattern in each layer. When the Star-of-David centers belonging to two adyacent layers are stacked in a honeycomb pattern, the system realizes a generalized Kane–Mele–Hubbard model in a regime where Dirac semimetallic states are subject to significant Mott–Hubbard interactions and spin–orbit coupling. At charge neutrality, the system is close to a quantum phase transition between a quantum spin Hall and an antiferromagnetic insulator. We identify a perpendicular electric field and the twisting angle as two knobs to control topology and spin–orbit coupling in the system. Their combination can drive it across hitherto unexplored grounds of correlated electron physics, including a quantum tricritical point and an exotic first-order topological phase transition.

电子相关性，自旋轨道耦合和拓扑结构的相互作用为实现量子物质的奇异状态提供了希望。蜂窝晶格上强相互作用的电子模型揭示了丰富的相图，这些相图具有非常规的量子态，包括手性超导性和与复杂磁阶交织在一起的相关量子自旋霍尔绝缘体。但是，这些电子状态的实质实现是稀缺的或不存在的。在这项工作中，我们提出并证明，将1T-TaSe ₂堆叠到双层中可以将电子从单层中的深Mott绝缘态限制到相关Dirac费米子系统，该系统受双层中相当大的自旋-轨道耦合影响。1T-TaSe ₂在每一层中形成大卫之星电荷密度波型。当属于两个相邻层的大卫之星中心以蜂窝状堆叠时，该系统在狄拉克半金属态经受显着的莫特-哈伯德相互作用和自旋轨道的状态下实现了广义的凯恩-梅勒-哈伯德模型耦合。在电荷中性的情况下，该系统接近量子自旋霍尔和反铁磁绝缘体之间的量子相变。我们将垂直电场和扭转角确定为两个旋钮，以控制系统中的拓扑和自旋轨道耦合。它们的结合可以驱动它穿越相关电子物理学的迄今尚未探索的领域，包括量子三临界点和奇异的一阶拓扑相变。