  The ability to prepare desired states without allowing time for the atomic
system to spontaneously decay to the ground state is limited by the fact that
Hamiltonian controls cannot affect the purity of the state in question. In this
paper, we discuss how a continuous off-resonant electromagnetic wave can be
used to prepare a desired final quantum state. With the aid of plasmonic
surface-enhancement, by placing a two-level atomic system near a gold
nanoparticle, preparation is accomplished in a reduced period of time and with
lower electric field intensity while the system purity is improved when
compared to an isolated system.
