Multi-flavor QED3 as the Quantum Plateau Transitions of Fractional Chern Insulators

Recent experiments in graphene hetro-structures have revealed the existence of Chern Insulators - integer and fractional Quantum Hall states made possible by the presence of a periodic substrate potential. Here we show that the new kinds of quantum critical points are enabled by the interplay of magnetic fields, interactions and the periodic potential. We discuss transitions between distinct quantized Hall states using both microscopic models and effective field theories, and highlight two important differences from the well studied disorder driven plateau transition. (i) First, the periodic potential, rather than disorder, enables a change in the Hall conductance at a fixed magnetic field and electron density and (ii) the presence of translation symmetry allows for direct transitions between quantum Hall states that otherwise require fine tuning. Transitions between particle-hole conjugate Jain states take the form of `pure' QED3 with multiple flavors of Dirac fermions.