Key points are not available for this paper at this time.
The low-energy collective excitations of semiconductors and insulators often couple strongly to light, allowing them to be probed optically. We argue here that in fractional Chern insulators intraband collective excitations are dark in the sense that they couple anomalously weakly to light. Using this property, we establish a general relationship between flat-band Chern numbers, quantum geometry, and spatial correlations in fractional-Chern-insulator states.
Wolf et al. (Tue,) studied this question.