A simple model for the vibrational modes in honeycomb lattices

The classical lattice dynamics of honeycomb lattices is studied in the harmonic approximation. Interactions between nearest neighbours are represented by springs connecting them. A short and necessary introduction of the lattice structure is presented. The dynamical matrix of the vibrational modes is then derived and its eigenvalue problem is solved analytically. The solution may provide deeper insight into the nature of the vibrational modes. Numerical results for the vibrational frequencies are presented. To show how effective our method for the honeycomb lattice is, we also apply it to triangular and square lattice structures. A few suggested problems are listed in the concluding section.