  Recently, we have determined the spectrum and the wave functions of the
Hamiltonian of a Landau particle with time-dependent mass and frequency
undergoing the influence of a uniform time-dependent electric field[J. Math.
Phys. 56, 072104 (2018)]. In the present paper we extend the study of this
model that we name the time-dependent Landau problem into the context of
coherent states. By means of the traditional factorization method of the
eigenfunctions of this system expressed in terms of the generalized Laguerre
polynomials, we derive the generators of the su(1,1) Lie algebra and we
construct the coherent states a la Barut-Girardello. These states are shown to
satisfy the Klauder's mathematical requirement to build coherent states and
some of their statistical properties are calculated and analyzed. We find that
these states are sub-Poissonian in nature. We show that, addition of photons
from these coherent states, increases the statistical properties and changes
the mathematical properties of these states.
