Signatures of unconventional superconductivity near reentrant and fractional quantum anomalous Hall insulators

Fan Xu; Zheng Sun; Jiayi Li; Ce Zheng; Cheng Xu; Jingjing Gao; Tongtong Jia; Yanfei Su; Kenji Watanabe; Takashi Taniguchi; Bingbing Tong; Li Lu; Jinfeng Jia; Zhiwen Shi; Shengwei Jiang; Junhao Lin; Yuanbo Zhang; Yang Zhang; Shiming Lei; Xiaoxue Liu; Tingxin Li

arXiv · 2504.06972

Signatures of unconventional superconductivity near reentrant and fractional quantum anomalous Hall insulators

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Abstract

Two-dimensional moir\'e Chern bands provide an exceptional platform for exploring a variety of many-body quantum phases at zero magnetic field within a lattice system. One particular intriguing possibility is that flat Chern bands can, in principle, support exotic superconducting phases together with fractional topological phases. Here, we report the observation of integer and fractional quantum anomalous Hall effects, the reentrant quantum anomalous Hall effect, and superconductivity within the first moir\'e Chern band of twisted bilayer MoTe2. The superconducting phase emerges from a normal state exhibiting anomalous Hall effects. Our results present the first example of superconductivity emerging within a flat Chern band that simultaneously hosts fractional quantum anomalous effects, a phenomenon never observed in any other systems. Our work expands the understanding of emergent quantum phenomena in moir\'e Chern bands, and offers a nearly ideal platform for engineering Majorana and parafermion zero modes in gate-controlled hybrid devices.

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Fan Xu, Zheng Sun, Jiayi Li, Ce Zheng, Cheng Xu, Jingjing Gao, Tongtong Jia, Yanfei Su, Kenji Watanabe, Takashi Taniguchi, Bingbing Tong, Li Lu, Jinfeng Jia, Zhiwen Shi, Shengwei Jiang, Junhao Lin, Yuanbo Zhang, Yang Zhang, Shiming Lei, Xiaoxue Liu, Tingxin Li. 2025-04-09. Signatures of unconventional superconductivity near reentrant and fractional quantum anomalous Hall insulators. https://arxiv.org/abs/2504.06972

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