  Using the Lewis-Riesenfeld method of invariants we construct explicit
analytical solutions for the massless Dirac equation in 2+1 dimensions
describing quasi-particles in graphene. The Hamiltonian of the system
considered contains some explicit time-dependence in addition to one resulting
from being minimally coupled to a time-dependent magnetic field. The eigenvalue
equations for the two spinor components of the Lewis-Riesenfeld invariant are
found to decouple into a pair of supersymmetric invariants in a similar fashion
as the known decoupling for the time-independent Dirac Hamiltonians.
