  We calculate the dynamics of a nanomechanical oscillator (NMO) coupled
capacitively to a Cooper pair box (CPB), by solving a stochastic Schrodinger
equation with two Lindblad operators. Both the NMO and the CPB are assumed
dissipative, and the coupling is treated within the rotating wave
approximation. We show numerically that, if the CPB decay time is smaller than
the NMO decay time, the coupled NMO will lose energy faster, and the coupled
CPB more slowly, than do the uncoupled NMO and CPB. The results show that the
efficiency of energy loss by an NMO can be substantially increased if the NMO
is coupled to a CPB.
