We show that a wide class of quantum systems with translational
invariance can host dispersionless, soliton-like, wave packets. We
focus on the setting where the effective, two-dimensional Hamiltonian
acquires the form of the Dirac operator. The proposed framework for
construction of the dispersionless wave packets is illustrated on
silicene-like systems with topologically nontrivial effective mass.
The talk is based on a joint work with Vít Jakubský.