Orbital diamagnetism in multilayer graphenes: Systematic study with the effective mass approximation

We present a theoretical study on the orbital magnetism in multilayer graphenes within the effective mass approximation. The Hamiltonian and thus susceptibility can be decomposed into contributions from subsystems equivalent to monolayer or bilayer graphene. The monolayer-type subband exists only in odd layers and exhibits a delta-function susceptibility at ₅=0. The bilayer-type subband appearing in every layer number gives a singular structure in the vicinity of ₅=0 due to the trigonal warping as well as a logarithmic tail away from ₅=0. The integral of the susceptibility over energy is approximately given only by the layer number.