Quantum spin Hall (QSH) insulators are two-dimensional electronic materials that have a bulk band gap similar to an ordinary insulator but have topologically protected pairs of edge modes of opposite chiralities^1,2,3,4,5,6. So far, experimental studies have found only integer QSH insulators with counter-propagating up-spins and down-spins at each edge leading to a quantized conductance G₀ = e²/h (with e and h denoting the electron charge and Planck’s constant, respectively)^{7,8,9,10,11,12,13,14}. Here we report transport evidence of a fractional QSH insulator in 2.1° twisted bilayer MoTe₂, which supports spin-S_z conservation and flat spin-contrasting Chern bands^15,16. At filling factor ν = 3 of the moiré valence bands, each edge contributes a conductance \(\frac{3}{2}{G}_{0}\) with zero anomalous Hall conductivity. The state is probably a time-reversal pair of the even-denominator 3/2-fractional Chern insulators. Furthermore, at ν = 2, 4 and 6, we observe a single, double and triple QSH insulator with each edge contributing a conductance G₀, 2G₀ and 3G₀, respectively. Our results open up the possibility of realizing time-reversal symmetric non-abelian anyons and other unexpected topological phases in highly tunable moiré materials^17,18,19.

量子自旋霍尔 (QSH) 绝缘体是二维电子材料，具有与普通绝缘体类似的体带隙，但具有拓扑保护的相反手性边缘模式对^1,2,3,4,5,6。到目前为止，实验研究仅发现整数 QSH 绝缘体在每个边缘具有反向传播的上自旋和下自旋，从而导致量子化电导G ₀  =  e ² / h（其中e和h表示电子电荷和普朗克常数，分别）^{7,8,9,10,11,12,13,14}。在这里，我们报告了 2.1° 扭曲双层 MoTe ₂中分数 QSH 绝缘体的输运证据，它支持自旋S _z守恒和平自旋对比陈能带^15,16。在 莫尔价带的填充因子ν = 3 时，每个边缘贡献一个电导\(\frac{3}{2}{G}_{0}\)，反常霍尔电导率为零。该状态可能是偶数分母 3/2 小数陈绝缘体的时间反转对。此外，在ν  =  2、4 和 6 时，我们观察到单、双和三 QSH 绝缘体，每个边缘分别贡献电导G ₀、2 G ₀和 3 G ₀。我们的结果开辟了在高度可调莫尔材料中实现时间反转对称非阿贝尔任意子和其他意想不到的拓扑相的可能性^17,18,19。