Theory for optical Hall conductivity in the trilayer graphene in the quantum Hall regime

We theoretically study optical Hall conductivities for ABA and ABC trilayer graphenes. In ABA-stacked trilayer, the resonance spectrum is shown to be a superposition of effective monolayer and bilayer contributions with band gaps, while ABC trilayer exhibits a distinct spectrum peculiar to the cubic-dispersed bands with a strong trigonal warping, where we found the signals associated with low-energy Dirac cones are conspicuous enough to be directly observable owing to a large Lifshitz-transition energy (∼ 10 meV). We have also revealed how the presence or absence of the inversion symmetry affects the optical Hall conductivities.