  Various schemes have been proposed to overcome the drawback of the
decoherence on quantum-enhanced parameter estimation. Here we suggest an
alternative method, quantum feedback, to enhance the parameter precision of
optimal quantum estimation of a dissipative qubit by investigating its dynamics
of quantum Fisher information. We find that compared with the case without
feedback, the quantum Fisher information of the dissipative qubit in the case
of feedback has a large maximum value in time evolution and a smaller decay
rate in the long time.
