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

TL;DR

This paper reports the first observation of superconductivity within a flat Chern band that also exhibits fractional quantum anomalous Hall effects in twisted bilayer MoTe2, revealing new quantum phenomena in moiré materials.

Contribution

It demonstrates superconductivity coexisting with fractional quantum anomalous Hall effects in a moiré Chern band, a novel phenomenon not previously observed.

Findings

Observation of integer and fractional quantum anomalous Hall effects

Reentrant quantum anomalous Hall effect observed

Superconductivity emerges from a state with anomalous Hall effects

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.