ABSTRACT
The essential low-energy properties are described by the 3D anisotropic spiral Dirac cones. However, the dimensional crossover of electronic properties is absent in the rhombohedral graphites stacking. Moreover, the sombrero-shaped subbands, irrelevant to the rhombohedral graphite, are evidence of the 3D to 2D transition. In a hexagonal unit cell with P3 symmetry, the energy dispersions of the rhombohedral graphite are depicted along different symmetric directions. The low-energy electronic properties in the bulk graphite are described by the 3D anisotropic Dirac cones tilted relative to kztrue. The absorption spectrum of rhombohedral graphite reflects the Dirac-cone energy dispersions. The Onsager quantization rule is used to obtain the quantized energies for the Landau states of an isoenergetic surface along the Dirac point spiral. The Landau subband spectra in rhombohedral graphite are calculated using a diagonalization scheme designed for the Peierls tight-binding Hamiltonian in the representation of the triple hexagonal unit cell.
