Phase Transitions in Tetralayer Graphene at Charge Neutrality

As Bernal-stacked tetralayer graphene (4LG) hosts two intersecting massive Dirac bands, it supports an excellent platform for investigating multiband transport. Here we report studies on 4LG at the lowest Landau level half-filling in very high magnetic field, where the effect of Coulomb interactions is considerable. By exploring the dependence on magnetic and displacement fields of ν=0 quantum Hall state, the experimental result presents intriguing phase diagram of ground states. In particular, the tilted field magnetotransport reveals the interplay between crystal symmetry and Coulomb interactions in multiple Dirac band systems.