Control of coherent states of quantum systems with a square hamiltonian

The paper is concerned with control of wherent states of quantum systems described by a Hamiltonian of the form $\mathcal{H}(t)=QB(t)Q+u(t)Q$. Solutions are obtained for cases where the control functions are $B(t)$ and $u(t)$. The theoretical reasoning is illustrated with description of controlling the coherentistates of a charged particle in the electromagnetic field ol an a.c. solenoid.