  In this paper we construct the generalized coherent states for an electron in
monolayer or bilayer graphene placed in an external magnetic field. At first we
define an appropriate set of ladder operators acting on the eigenfunctions for
each Hamiltonian, afterwards we derive the generalized coherent states through
several definitions and analyze the commutation relationship between the ladder
operators. Then we determine the conditions leading to the mutual equivalence
between coherent states. Finally, some physical quantities are calculated and
we study the time evolution for the generalized graphene coherent states.
