  In terms of the exact quantum master equation solution for open electronic
systems, the coherent dynamics of two charge states described by two parallel
quantum dots with one fully polarized electron on either dot is investigated in
the presence of spin-orbit interaction. We demonstrate that the double dot
system can stay in a dynamically decoherence free space. The coherence between
two double dot charge states can be precisely manipulated through a spin-orbit
coupling. The effects of the temperature, the finite bandwidth of lead, and the
energy deviations during the coherence manipulation are also explored.
