Van der Waals materials offer unprecedented control of electronic properties via stacking of different types of two-dimensional materials. A fascinating frontier, largely unexplored, is the stacking of strongly correlated phases of matter. We study 4Hb-TaS₂, which naturally realizes an alternating stacking of 1T-TaS₂ and 1H-TaS₂ structures. The former is a well-known Mott insulator, which has recently been proposed to host a gapless spin-liquid ground state. The latter is a superconductor known to also host a competing charge density wave state. This raises the question of how these two components affect each other when stacked together. We find a superconductor with a T_c of 2.7 Kelvin and anomalous properties, of which the most notable one is a signature of time-reversal symmetry breaking, abruptly appearing at the superconducting transition. This observation is consistent with a chiral superconducting state.

范德华材料通过堆叠不同类型的二维材料，提供了前所未有的电子性能控制。高度相关的物相的堆积是一个令人着迷的前沿领域，在很大程度上尚未被探索。我们研究了4Hb-TaS ₂，它自然实现了1T-TaS ₂和1H-TaS ₂结构的交替堆叠。前者是著名的莫特绝缘子，最近已提出它具有无间隙的自旋液体基态。后者是已知也具有竞争电荷密度波状态的超导体。这就提出了以下问题：这两个组件堆叠在一起时如何相互影响。我们发现一个具有T _c的超导体2.7开尔文和反常性质，其中最显着的特征是时间逆转对称性破坏的标志，突然出现在超导转变处。该观察结果与手性超导状态一致。