  The ability of an environment to assist in one-photon phase control relies
upon entanglement between the system and bath and on the breaking of the time
reversal symmetry. Here, one photon phase control is examined analytically and
numerically in a model system, allowing an analysis of the relative strength of
these contributions. Further, the significant role of non-Markovian dynamics
and of moderate system-bath coupling in enhancing one-photon phase control is
demonstrated, and an explicit role for quantum mechanics is noted in the
existence of initial non-zero stationary coherences. Finally, desirable
conditions are shown to be required to observe such environmentally assisted
control, since the system will naturally equilibrate with its environment at
longer times, ultimately resulting in the loss of phase control.
