  When the nonlinearity of nanomechanical resonator is not negligible, the
quantum decoherence of charge qubit is studied analytically. Using nonlinear
Jaynes-Cummings model, one explores the possibility of being quantum data bus
for nonlinear nanomechanical resonator, the nonlinearity destroys the dynamical
quantum information-storage and maintains the revival of quantum coherence of
charge qubit. With the calculation of decoherence factor, we demonstrate the
influence of the nonlinearity of nanomechanical resonator on engineered
decoherence of charge qubit.
