Observation of fractional quantum anomalous Hall effect*

The synergy of topology, strong correlations, and spontaneous symmetry breaking can give rise to exotic quantum states of matter. A celebrated example is the rationally designed flat Chern band, which hosts fractional Chern insulators. These insulators can exhibit the fractional quantum anomalous Hall effect(FQAHE), which is the lattice analog of the fractional quantum Hall effect at zero magnetic field without Landau level formation. In this talk, I will present the experimental observation of high-temperature FQAHE in twisted MoTe₂ bilayer, using combined magneto-optical spectroscopy and transport measurements. Additionally, I will present an anomalous Hall state around the filling factor of -1/2, the leading candidate for which is a composite Fermi liquid state. Notably, the states associated with the FQAH and associated effects can be electrically tuned into a variety of topologically trivial phases. These results mark a promising direction for the investigation of charge fractionalization and anyon statistics at zero magnetic field and elevated temperature.