Tunable topological phenomenon in ABCA-tetralayer graphene

Rhombohedral multilayer graphene, stacking in an ABCABC... sequence, exhibits highly flat electronic bands in the vicinity of the charge neutral point, and is therefore anticipated to manifest strong Coulomb interactions. In this talk, we will show our recent experimental results on ABCA-tetralayer graphene. Rich broken-symmetry states associated with tunable topology in such system are observed through electrical transport measurement.