The unique properties of the half-filled Chern band

In this talk I will address the half filled Chern band, studied experimentally in twisted MoTe2 and in pentalayer Graphene. I will distinguish between the phases it forms for weakly-interacting and strongly-interacting electrons, and focus on the latter case, particularly on the "composite Fermi liquid" phase. I will analyze the unique properties of this state. I will show that despite being a metallic state, it has no Drude weight (i.e., no $DC$ conductivity in the absence of impurities) and it carries a gapped Plasma mode. Finally, I will discuss the phase transitions observed between the various phases when temperature and displacement field are varied, and the transitions to neighboring Fractional Chern Insulator phases.

This will NOT be a technical talk. If you understood the abstract, you will understand the talk.